| ??? 03/02/09 02:14 Read: times |
#162992 - thank you Responding to: ???'s previous message |
Thank you for the reply. It looks like the TI bit wasn't included in the sample code I was using to test my MAX232 circuit. I have changed the code to the following:
$MOD831 CSEG ORG 0000h LJMP BEGIN ORG 40h BEGIN: MOV SCON,#01110000B ; Mode 1/Stop b/Rec en/x/x/Flags MOV TH1,#0FDh ; Reload value for 9600 Bd MOV TCON,#01010101B ; Fl1/Tim1 on/Fl0/Tim0 on/Ext1-edge/Ext0-edge MOV TMOD,#00100001B ; Gate1/Timer/Mode 2/Gate0/Timer/Mode 1 START: JNB RI,$ ; Sit here and wait for the Rx. Int. bit to go high MOV A,SBUF ; Move the rcv'd character to the acc. CLR RI ; Clear the Rx. Int. bit CLR TI ; Clear the Tx. Int. bit MOV SBUF,A ; Send out the rcv'd character JNB TI,$ ; Wait here until the Tx is complete LJMP START ; Jump back to Start to repeat the process I still do not get anything back from the uC when I send it a character from HyperTerm using this program. I am clearly missing something here. Thoughts? |
| Topic | Author | Date |
| serial comm problem | 01/01/70 00:00 | |
| what about TI? | 01/01/70 00:00 | |
| thank you | 01/01/70 00:00 | |
| Be better... | 01/01/70 00:00 | |
| no luck | 01/01/70 00:00 | |
| Settings | 01/01/70 00:00 | |
| What is your XTAL frequency ? | 01/01/70 00:00 | |
| parity and XTAL | 01/01/70 00:00 | |
| Eh ? | 01/01/70 00:00 | |
| one or the other | 01/01/70 00:00 | |
| my mistake | 01/01/70 00:00 | |
| scope pictures | 01/01/70 00:00 | |
| whatizit? | 01/01/70 00:00 | |
| where I measured it... | 01/01/70 00:00 | |
| waveforms look OK | 01/01/70 00:00 | |
| question | 01/01/70 00:00 | |
| LSBit comes first after startbit | 01/01/70 00:00 | |
| cable | 01/01/70 00:00 | |
| isolation and ESD protection | 01/01/70 00:00 | |
I have blown very few, if any, MAX232's | 01/01/70 00:00 | |
| Your scope trace looks normal | 01/01/70 00:00 | |
| more pics | 01/01/70 00:00 | |
| show picture at PC side | 01/01/70 00:00 |