This seems a common scenario - new circuit, Picaxe soldered in, can't download a program to it. So to save everyone's time, I've been through as much debugging as I can think of, and I think I've found the problem (or at least a problem).
Picaxe (28X1 SMT) has power, reset pin is high, resonator connected, resistors on download circuit seem fine, the download cable (AXE027) checks out, it can be used to program another Picaxe on a different test board and there's continuity from the D female socket to the pins on the Picaxe.
Now, here's what I think is the problem. With download cable and power plugged in, I read -0.5V at the serial in pin, 0V at the serial out. Reading around the forums suggests that I should have 5.5V at the serial out pin. Hippy's page on serial comms suggests that connecting the serial out to 0V can damage the Picaxe, and I certainly did that when sorting my wiring out. Given that the Picaxe is soldered in (and SMT), then I can't pull it out of the circuit and drop it into a test board.
So, my theory is that I've buggered the picaxe though connecting the serial out to 0V. How could I tell if I'm right or wrong?
Picaxe (28X1 SMT) has power, reset pin is high, resonator connected, resistors on download circuit seem fine, the download cable (AXE027) checks out, it can be used to program another Picaxe on a different test board and there's continuity from the D female socket to the pins on the Picaxe.
Now, here's what I think is the problem. With download cable and power plugged in, I read -0.5V at the serial in pin, 0V at the serial out. Reading around the forums suggests that I should have 5.5V at the serial out pin. Hippy's page on serial comms suggests that connecting the serial out to 0V can damage the Picaxe, and I certainly did that when sorting my wiring out. Given that the Picaxe is soldered in (and SMT), then I can't pull it out of the circuit and drop it into a test board.
So, my theory is that I've buggered the picaxe though connecting the serial out to 0V. How could I tell if I'm right or wrong?
Last edited: