Hi Cherokee,
I see that Vianney has a suggestion, for how I might get the HL7692 firmware version 2.27 installer to work, to upgrade from the version 2.23 that our HL7692 came with. I’ll try that suggestion now.
Meanwhile, I’ve made a bit of a discovery, by experimenting, with why commands sometimes receive no response.
It’s looking like the HL7692 UART receive buffer, hardware or firmware, is occasionally being left with something within (could be whole previous message, could be partial message, perhaps the 0D at the end). Or, extraneous data is getting into the buffer.
A ‘workaround’ I’ve found, is before each command, to send a command comprising two CR characters. And then wait 40 ms, before sending the command I want. A wait of 35 ms or lower is found not to suffice.
Just one CR is found not to be enough. Nor is instead sending one or two CR characters at the start of each command (eg CR CR ATI3 CR). That certainly improves matters. But some unreliability remains.
Our transmit and receive pin signals, from MCU to the HL7692, look good, when we sniff with a comms monitor. We see the characters we expect.
We see no such problem when our MCU talks instead to an HL7800, using the same pins, with either HL7800 version 1.7.14 or 4.3.9.0 firmware. We see other problems with that firmware, but that’s another story.
Best regards,
David