;*************************************************************************** ;* Title: AVR_UI_TNC EXAMPLE CODE Version 1.7 ;* Made available for educational, and non-commercial use. ;* Commercial use forbidden without license from author. ;* Code may be modified as long as it is released publicly and credit ;* is given to the original author(s). ;* (c) copyright 2000 Henry Carl Ott N2RVQ, all Rights reserved. ;* Questions, comments or offers of cash? carlott@si.rr.com http://users.rcn.com/carlott/ ;*************************************************************************** ;* Description: Example code to test basic UI packet functions on an AT90s2313 / MXCOMM MX-614 combo. ;* Please reference separate documents for schematics / hardware description. ;* Provides minimal tnc functionality for ui-frames. ;* Outputs received ax25 packets to console (total packet length 224 chars including path) ;* Transmits strings from console, max length, 96 chars not including path ;* Beacons at user determined intervals, beacon text up to 64 chars of eeprom stored message ;* Console configuration of mycall, ui destination and digi path, ;* beacon text (max 64 chars),beacon time, and console echo ;************************************************************************** ;* Credits: The main inspiration for the design was the TAPR PIC-E project. ;* I had used Microchip MCUs in a number of other projects, but I was currently ;* experimenting with Atmel AVR MCUs and found that the additional RAM/EPROM and ;* additional indexing modes made code development easier (at least for me). Besides I ;* was getting tired of all the bank switching on the PICs :). ;* For the software I looked very closely at the PIC-E code posted by ;* Byon Garrabrant, John Hansen, Mike Berg and others (sorry if I missed anyone). ;* The jump table decoding was inspired by Byons code, and the CRC calculation ;* is an almost direct port of his crc routine. ;*************************************************************************** ;* REVISIONS: ;*1.0 first release ;*1.1 cut a few cycles in rx isr to try to try to avoid overloading ;*1.2 put rx crc routine inline within rx-isr to speed up isr ;*1.5 changed code to support SPI FM25160 FRAM part instead of the I2C PCF8583 ;* with the lack of the rtc, we simplified the beacon timer (just on or off) ;* NOTE: Be sure to reference the rev 1.5 schematic ;*1.6 bug fixes, changed string reception routine to be int driven. misc tweaks ;*1.7 fixed beacon text bug, added non volitile converse mode flag bit ;*************************************************************************** ;* Disclaimer: I'm a lousy programmer. Please don't use this code/design for any ;* application where human life is at risk or property damage may occur. ;*************************************************************************** ; Console command descriptions: ; Commands are case insensitive. ; In most cases only the first letter of command is significant ; ; Mycall examples 'Mycall NOCALL-1' or 'M NOCALL' ; Unproto examples 'UNPROTO APRS VIA RELAY,WIDE5-5' or 'U APRS V WIDE' or 'u apz001' ; Echo examples 'ECHO OFF' or 'ECHO ON' or 'e off' ; Beacon examples 'BEACON ON' 'BEACON OFF' 'B OFF' 'B ON' ; BText examples 'BTEXT Test Message' or 'BT THIS IS A TEST,' ; Converse examples 'C' or 'converse' or 'conv' Enters converse mode ; Id examples 'ID' or 'I' Sends a sample beacon (will key radio!) ;--- start of the actual code --- .nolist .include "2313def.inc" .list .listmac ;*************************************************************************** ;* ;* MACROS ;* ;*************************************************************************** ;--- simple led macros .macro led_grn sbi DDRD,led sbi PORTD,led .endm .macro led_red sbi DDRD,led cbi PORTD,led .endm .macro led_off cbi DDRD,led cbi PORTD,led .endm ;---- SPI macros .macro spi_data_inp cbi DDRD,SPI_data .endm .macro spi_data_out sbi DDRD,spi_data .endm ;--- mx-614 specific macros .macro tx_mx614 sbi PORTB,mode0 cbi PORTB,mode1 .endm .macro rx_mx614 cbi PORTB,mode0 sbi PORTB,mode1 .endm .macro off_mx614 sbi PORTB,mode0 ; power down mode sbi PORTB,mode1 .endm ;--- radio control .macro ptt_down sbi PORTB,rad_ptt .endm .macro ptt_up cbi PORTB,rad_ptt .endm ;--- send single char to console .macro _send ldi temp,@0 rcall putc .endm ;--- send string to console .macro _send_232_str ldi zh,high(@0 * 2) ldi zl,low(@0 * 2) ;Init Z-pointer rcall ser_ram_str .endm ;--- skip next instruction .macro skip rjmp (pc + 2) ; skip, next instruction .endm ;--- copy zero terminated eeprom string into fram (left shift data first) .macro _copy_ax_string_shift ldi temp,@0 rcall ax25_s_string .endm ;--- copy zero terminated eeprom string into fram .macro _copy_ax_string ldi temp,@0 rcall ax25_string .endm ;--- send zero terminated eeprom string to console .macro _232_str ldi temp,@0 rcall serial_string .endm ;------delay two cycles in one instruction .macro _nop_2 rjmp (pc + 1) .endm ;----------------------------------------------------------------- ;--- port and pin defines ;--- portb .equ rxd_614 = 0 ; I 614_rxd .equ sw_inp = 1 ; I sw_inp .equ txd_614 = 2 ; O 614_txd .equ det_614 = 3 ; O I 614_det .equ mic_ptt = 4 ; I mic ptt input .equ rad_ptt = 5 ; O radio ptt output .equ mode1 = 6 ; O mx614 mode 1 select .equ mode0 = 7 ; O mx614 mode 0 select ;--- portd .equ spi_port = PORTD .equ spi_sck = 6 ; O SPI clock .equ led = 5 ; O led_1 .equ spi_cs = 4 ; O SPI chip select .equ spi_data = 3 ; I/O SPI data .equ spare_232 = 2 ; I external rs232 input .equ txd_232 = 1 ; O 232_txd .equ rxd_232 = 0 ; I 232_rxd ;---- some program equates and constants .equ ram_begin = 0x60 ; start of ram on 2313 .equ random = 0xc1 ; storage for random number generator .equ pack_buff_0 = 0xc2 ; .equ pack_buff_1 = 0xc3 .equ pack_buff_2 = 0xc4 .equ pack_buff_3 = 0xc5 .equ ctrl_c = 0x03 .equ bs = 0x08 ; back space .equ bel = 0x07 ; bell .equ cr = 0x0d ; carriage return .equ lf = 0x0a ; line feed .equ clock = 8000000 ; cpu clock .equ console_baud = 9600 .equ isr_reload_val= (0xffff - (clock/9600)) + 19 .equ beacon_time = 235 ; fixed beacon reload value in 2.56 second multiples .equ fram_op_wren = 0b00000110 .equ fram_op_rd = 0b00000011 .equ fram_op_wr = 0b00000010 .equ tx_bank = 7 ; what fram bank to send packets from .equ tx_delay = 40 ; number of flag bytes before data .equ tail_flags = 2 ; number of flags to send after data .equ tx_hang = 1 ; delay (.001) after last flag before un-keying .equ min_packet_len = 18 ; minimum length, + con+pid and crc of rx packet .equ max_packet_len = 255 ; maximim length, determined by available ram, isr discards extra chars .equ max_str_len = 96 ; how much of avr ram to use for string storage .equ reload_count = 59 ; ax25 rxd transition time interval counter reload value, used by rx isr .equ control_byte = 0x03 ; control and pid for ax25 ui packets .equ pid_byte = 0xf0 ; ;***************************** ;* Global Register Variables * ;***************************** .def r0 = r00 ; used with lpm instruction .def tic = r01 ; incs @ 9600 hz resets at 96 0-95 .def sec_01 = r02 ; incs @ 100 hz .def b_timer = r03 ; decs at .256 hz, will not go past zero, used for beacon timer .def ax25_txbuff = r05 ; ax25 data to send .def ax25_ones = r06 ; no of continous ones sent, used for bit stuffing .def ax25_crc_lo = r07 ; crc calculation low order byte rx/tx .def ax25_crc_hi = r08 ; crc calculation hi order byte rx/tx .def packet_len = r09 ; length of received packet not including crc .def ax25_rxbuff = r10 ; used to assemble rx bytes .def ax25_rx_count = r11 ; time interval between transitions .def ax25_tx_bits = r12 ; number of bits to send .def isr_save = r15 ; saves mcu status reg during isr .def temp = r16 ; gp working reg .def temp2 = r17 ; yet another working register .def ii = r18 ; gp loop counter .def flags = r19 ; various bit flags and ax25_tx flags .def rx_flags = r20 ; bit flags used to communicate with isr .def ax25_rx_chars = r21 ; received chars ptr/counter (used only within isr) .def ax25_rx_bitcnt = r22 ; used to assemble individual bits into bytes .def EEaddr = r23 ; eeprom address .def EEdata = r24 ; eeprom data for rd/wr .def byte_cnt = r25 ; general purpose byte counter .def xl = r26 .def xh = r27 .def yl = r28 ; string pointer, used to assemble rs-232 string in uart isr .def fram_bank = r29 ; bank select on FM25160 (low three bits), hi four bits are used by isr! .def yh = r29 .def zl = r30 ; used for indirect indexing and a gp register otherwise .def zh = r31 ; used for indirect indexing and a gp register otherwise .def bitcnt = r31 ; gp bit counter, ;************************** ;- bit flags defined ;************************** .equ string_rx = 0x00 ; cr terminated string was received .equ ax25_flag = 0x01 ; sending flags? (no bit stuffing or crc) .equ ax25_shift = 0x02 ; do we shift the data before sending? (address) .equ fram_no_sei = 0x03 ; used to disable sei on fram return routines when called from an isr .equ conv_mode = 0x05 ; non volitile flag bit, if we were in converse mode on power down ; re-enter converse mode on power up .equ echo = 0x06 ; if set echo console chars .equ beacon_enable = 0x07 ; enable beacon ;------------------------- ;************************** ;- ax25 recieve bits defined ;************************** .equ old_bit = 0x00 ; previous bit sample .equ rx_enable = 0x01 ; enable reception of packet data .equ in_packet = 0x02 ; currently receiving packet data .equ half_flag = 0x03 ; set if last bit received was a zero (more of an 1/8 flag) .equ new_bit = 0x04 ; new bit sample, new and old bit must be in these positions .equ flag_det = 0x05 ; last byte was a valid flag ;------------------------- ;********************* ;* Interrupt Vectors * ;********************* .CSEG .org 0x00 rjmp reset ; Reset Handle .org INT0addr ; external int 0 ; bit bang secondary serial port reti .org INT1addr ; external int 1 reti .org OVF1addr ; overflow of 16 bit timer 1 basic 9600hz tic rjmp t1int .org OVF0addr ; overflow of 8 bit timer 0 reti .org URXCaddr ; reception of data by uart rjmp uart_rx_isr ;--- timer 1 overflow interupt ;--- we should hit the isr @ 9600 hz ;--- the isr handles the low level transmission of ax25 byte and assembles received packets t1int: in isr_save,SREG ; save SREG push temp push zl ; we have to use zl and zh for thejump table anyway push zh ; so we might as well use the for gp ldi zh,high(isr_reload_val) ; reload timer1 ldi zl,low(isr_reload_val) out tcnt1h,zh out tcnt1l,zl inc tic ; bump counter everytime through ;--- ax25 transmit portion of isr ax25_tx: tst ax25_tx_bits ; any bits to send? breq ax25_tx_end ; no, branch to end mov temp,tic ; 9600 divided by 8, see if we are in a tx bit period (1200 baud) andi temp,0x07 ; mask off hi bits brne ax25_tx_end ; nope, fall through sbrc flags,ax25_flag ; clr ax25_ones ; if a flag byte, no bit stuffing mov temp,ax25_ones cpi temp,5 ; check for bit stuffing brne send_bit ; no match keep going rcall ax25_tx_0 ; stuff a zero and exit rjmp ax25_tx_end ; send_bit: sbrc ax25_txbuff,0 ; test lsb inc ax25_ones ; if a one, don't change output, just bump the ones counter sbrs ax25_txbuff,0 ; test lsb, data is sent lsb first rcall ax25_tx_0 dec ax25_tx_bits ; number of bits left to send lsr ax25_txbuff ; shift next bit into tx position, bit just sent goes into carry sbrs flags,ax25_flag ; if a flag byte, don't calculate crc rcall ax25_calc_crc ; generate crc on carry bit ax25_tx_end: ;--- ax25 rx portion of isr ax25_rx: sbrs rx_flags,rx_enable ; is reception enabled? rjmp rx_reset_cnt ; no, jump to end sbis PINB,det_614 ; any dcd? rjmp rx_flush ; nope, reset registers tst ax25_rx_count ; test transition counter breq pc + 2 ; if @ zero, stay at zero dec ax25_rx_count cbr rx_flags,(1 << new_bit) sbic PINB,rxd_614 ; copy pin status sbr rx_flags,(1 << new_bit) mov temp,rx_flags swap temp ; moves old_bit and new_bit into same bit position eor temp,rx_flags sbrs temp,0 ; check for change rjmp ax25_rx_end ; nope rx_change: bst rx_flags,new_bit ; copy new_bit to old bld rx_flags,old_bit tst ax25_rx_count ; test for timout brne pc + 2 ; > 0 ? rjmp rx_flush ; timeout lsr ax25_rx_count lsr ax25_rx_count lsr ax25_rx_count ; divide count by 8 ldi zh,high(rx_jmp) ; ldi zl,low(rx_jmp) ; Init Z-pointer add zl,ax25_rx_count clr temp ; adc zh,temp ; if a carry from low order add it in ijmp ;--- jump table rx_jmp: rjmp rx_flag ;0 flag rjmp rx_add_5 ;1 zero stuff, add five ones toss zero rcall rx_add_1 ;2 11110 rcall rx_add_1 ;3 1110 rcall rx_add_1 ;4 110 rcall rx_add_1 ;5 10 rjmp rx_add_0 ;6 0 rjmp rx_flush ;7 error, too soon ;--- check that at least one bit has been received and that it was a zero ;--- if so a flag has been received, otherwise error rx_flag: sbrs rx_flags,half_flag ; check for first zero of flag rjmp rx_flush sbr rx_flags,(1 << flag_det); set flag detected flag cbr rx_flags,(1 << half_flag) ldi ax25_rx_bitcnt,8 ; reload bit counter for next byte sbrc rx_flags,in_packet ; are we currently within a packet? rjmp ax25_rx_close ; yes, try to close rjmp rx_reset_cnt ; just keep going ;--- add 5 ones to buffer, and discard extra stuffed zero rx_add_5: cbr rx_flags,(1<' ; make pretty clr zl ; load pointer of destination station rcall disp_call ldi zl,13 rcall fram_rd sbrc temp,0 ; any digis? rjmp disp_pack_data ; no, just display data digi_loop: ldi temp,',' rcall putc rcall disp_call ; display formatted call, ssid, will return with lsb of ssid location in carry brcc digi_loop ; keep looping disp_pack_data: _send ':' ; delim for data subi zl,-2 ; point past control and pid disp_pd_loop: cp packet_len,zl ; display the msg data breq disp_pd_end rcall fram_rd rcall putc rjmp disp_pd_loop disp_pd_end: rcall crlf ; new line ret ;--- display call and ssid on console ;--- z points to data, display 6 shifted chars, then ssid, ;--- returns with carry indicating lsb of ssid location disp_call: ldi ii,6 ; num of chars dp_loop: rcall fram_rd ; get char lsr temp ; cpi temp,' ' ; is space? breq pc + 2 ; don't ship rcall putc dec ii brne dp_loop rcall fram_rd mov ii,temp ; get ssid lsr ii ; shift off lsb andi ii,0x0f ; mask off top nibble breq ssid_end ; if ssid = zero display nothing _send '-' cpi ii,10 brlo ssid_1_9 _send '1' subi ii,10 ssid_1_9: mov temp,ii rcall send_nibble ssid_end: dec zl rcall fram_rd ; get ssid again lsr temp ; shift lsb into carry ret ;-------------------------------------------------------------------------------------- ;--- send zero terminated string from ram, string must start at fram_begin ;--- trashes xl,zl,packet_len,temp ;--- sends eepom stored ui path before string send_ram_string: andi fram_bank,0xf0 ; mask off bottonm bits ori fram_bank,tx_bank ; set to tx bank in fram rcall copy_path_fram ; start buildeing packet in fram ldi xl,ram_begin ; point to beginning of string send_str_loop: ld temp,x+ ; start copying ram msg to fram tst temp breq send_str_doit rcall fram_wr ; save it rjmp send_str_loop send_str_doit: mov packet_len,zl rcall send_packet send_str_end: ret ;--- check beacon for time out(if enabled) , check_beacon: sbrs flags,beacon_enable rjmp check_b_end ; if beacon is not enabled tst b_timer ; is beacon timer at zero? breq send_beacon check_b_end: ret ;--------------------------------------------- ;--- send beacon text, reset beacon timer send_beacon: andi fram_bank,0xf0 ; mask off bottonm bits ori fram_bank,tx_bank ; set to high bank in fram rcall copy_path_fram ; start building build msg in fram _copy_ax_string _b_text ; copy the message text beaconl_1: mov packet_len,zl rcall send_packet rcall display_packet ; display on local console ldi temp,beacon_time mov b_timer,temp ; ret ;--- copy path from eeprom to already selected fram_bank ;--- add control and pid bytes copy_path_fram: clr zl ; point to beggining of fram _copy_ax_string_shift _dest ; copy destination shifted _copy_ax_string_shift _mycall ; copy mycall from eeprom _copy_ax_string_shift _digi ; copy digi path (if any) dec zl ; point last char of path rcall fram_rd ; get last char dec zl ; undo the inc zl at the end of the last read ori temp,0x01 ; set lsb to indicate end of path rcall fram_wr ldi temp,control_byte ; write control rcall fram_wr ldi temp,pid_byte ; write pid rcall fram_wr ret ;--- send packet from fram, packet must start fram_begin, fram_bank must be set properly ;--- packet_len contains length total length send_packet: rcall wait_dcd ; wait for clear channel cbr rx_flags,(1 << rx_enable) ; disable receive (rx routine will change crc registers) tx_mx614 ; change mode on modem chip ptt_down ; key the radio ldi ii,tx_delay rcall send_ax_flags ; initial delay ldi temp,0xff mov ax25_crc_lo,temp ; init crc mov ax25_crc_hi,temp mov ii,packet_len ; get message length clr zl ; pointer to start of message send_p_loop: rcall fram_rd ; get char rcall put_ax ; send char dec ii brne send_p_loop rcall send_ax_crc ldi ii,tail_flags ; send final flag bytes rcall send_ax_flags ldi temp,tx_hang rcall del_hunds ptt_up ; release ptt rx_mx614 ; back to rx mode cbi PORTB,txd_614 ; clear data out line, if high mx614 sends backchannel tone sbr rx_flags,(1 << rx_enable) ret ;--- send calculated crc, lo byte first send_ax_crc: rcall ax25_tx_wait ; wait for last char to be sent, otherwise crc is in-correct com ax25_crc_lo ; invert calculated crc com ax25_crc_hi push ax25_crc_hi ; save hi because it will get trashed when we send lo mov temp,ax25_crc_lo rcall put_ax ; ship lo pop temp ; get saved hi rcall put_ax ; and send hi ret ;--- send ii number of flag bytes send_ax_flags: rcall ax25_tx_wait ; wait till all all data is sent sbr flags,(1 << ax25_flag) ; set flag bit to disble bit stuffing and crc ldi temp,0x7e rcall put_ax dec ii brne send_ax_flags rcall ax25_tx_wait cbr flags,(1 << ax25_flag) ; wait until last bit ships to clear flag bit ret ;--- wait for carrier det to drop, then wait a random period, re-check carrier det pin. wait_dcd: ;rcall disp_any_packets sbic PINB,det_614 ; check pin rjmp wait_dcd rcall get_random andi temp,0b00111000 ; just some random delay rcall del_hunds sbic PINB,det_614 ; check pin again rjmp wait_dcd ret ;--- get toggle switch position ;--- charge cap on input pin, switch pin to input, ;--- see how long cap takes to discharge get_switch: tst tic ; wait for tic = 0 brne pc - 1 cbi DDRB,sw_inp ; make pin an input cbi PORTB,sw_inp ; turn off pull up current sbic PINB,sw_inp ; wait for cap to discharge rjmp pc -1 ldi temp,2 ; switch down sbrc tic,3 ; < 8? ldi temp,0 ; switch up sbrc tic,4 ; < 0x10? ldi temp,1 ; switch middle sbi PORTB,sw_inp sbi DDRB,sw_inp ; charge cap for next time sei ret ; get a pseudo random 8 bit value via linear congruential algorithm ; ported from pic code posted by Nikolai Golovchenko ; trashes ii, returns random value in temp get_random: lds temp,random ; get last value from ram mov ii,temp ; save in both ii and temp lsl ii swap ii andi ii,0xE0 add temp,ii add temp,ii add temp,ii ldi ii,0x35 sub temp,ii sts random,temp ret ;--- set zl to first char of arg, ii pos_zl: ldi zl,ram_begin ; point to beginning pos_zl_loop: rcall next_arg dec ii brne pos_zl_loop ret ;--- count total number of parameters in string, parameters are seperated by ' ' or ',' count_param: clr byte_cnt ldi zl,ram_begin ; point to beginning count_p_loop: rcall next_arg ld temp,z brne pc + 2 ret inc byte_cnt rjmp count_p_loop ;--- inc zl till a non-white char or ',' is encountered discard_white: ld temp,z cpi temp,' ' breq discard_loop cpi temp,',' breq discard_loop ret discard_loop: inc zl ; point to to next location rjmp discard_white ; inc zl till a ' ',',', or end of string discard_nw: ld temp,z tst temp ; test for zero termination breq discard_end cpi temp,',' breq discard_end cpi temp,' ' breq discard_end inc zl rjmp discard_nw discard_end: ret ; position zl at first char of next argument next_arg: ld temp,z tst temp brne pc + 2 ; test for end of string ret cpi temp,' ' breq pc + 2 rcall discard_nw rcall discard_white next_arg_end: ret ;---------------------------------------------------- ;---- delay temp * 10 ms (approx) del_hunds: add temp,sec_01 del_h_loop: cpse temp,sec_01 rjmp del_h_loop ret ;---------------------------------------------------- ;--- send a cr and lf to console crlf: ldi temp,cr rcall putc ldi temp,lf rcall putc ret ;---- put char to console putc: sbis USR,UDRE ;Is UART transmitter ready? rjmp putc ;If not, wait out UDR,temp ;Put character to UART ret ;--- wait for ax25_txbits = 0 then load buffer and set bit put_ax: rcall ax25_tx_wait mov ax25_txbuff,temp ldi temp,0x08 mov ax25_tx_bits,temp ; 8 bits to send, start ret ;--- wait for buffer to empty/last bit was sent ax25_tx_wait: tst ax25_tx_bits brne ax25_tx_wait ret ;--- convert temp to upper case to_upper: cpi temp,'a' brlo toupper_end cpi temp,'z'+1 brsh toupper_end subi temp,' ' toupper_end: ret ;-------------------------------------- ;--- send byte to console as two asc chars send_byte: push temp ; save temp rcall send_hi_nibble ; send hi nibble pop temp ; reget data push temp ; and save it again rcall send_nibble pop temp ; just restores temp ret ; fall into send nibble ;---------------------------------------- ;--- send low nibble as ascii send_hi_nibble: swap temp send_nibble: rcall hex_asc rcall putc ret ;-------------------------- ;--- routine converts 0-f hex in temp to 0 to F ascii hex_asc: andi temp,0b00001111 ;lower nybble only cpi temp,10 ;0-9 or A-F? brlo hex_asc_1 ; subi temp,-7 ;adjust A-F hex_asc_1: subi temp,-48 ;add offset to convert to ascii ret ;------------------------------------------------ ;--- convert asci char in temp to 0-15 nibble ;--- set carry if char is invalid (not 0-9 or a-f) asc_hex: rcall to_upper ; convert to upper case cpi temp,'F'+1 ; test for 'E' and above brsh asc_error cpi temp,'A' brsh asc_letters cpi temp,'9'+1 brsh asc_error cpi temp,'0' brsh asc_numbers asc_error: sec ; set carry to indicate error ret ; and out asc_letters: subi temp,0x07 ;A-F ('0'+7) is the same as ('A' - 10) asc_numbers: subi temp,'0' ;0-9 ret ; and out ;----- random write temp to address pointed to by zl ;----- post inc zl fram_wr_no_sei: sbr flags,(1<