Hi all
I have a simple circuit with an 08m2 flashing 3 LEDs in sequence. It works fine on breadboard, using a small programmer breakout I etched myself (with 22k and 10k resistors plus stereo jack) slotted into the breadboard, with the LEDs connected to the pins on the breakout board.
Then I tried etching a small PCB to transfer the circuit to it.
At this point, the circuit does this...
First LED come on for a few seconds. Then they start to flash in sequence. If I switch off and on, first LED lights for a few seconds and then they flash. Or sometimes mid sequence the first LED will come on for a few seconds and then the sequence kicks in again. Or first LED comes on and stays on indefinitely...
I have tried two copies of the etched board, and they both exhibit this behaviour. I have checked and rechecked every single connection using multimeter and continuity tester. I can't find any shorts or anything else odd.
The only thing I can think of is that maybe it's to do with having the serial in and serial out pins floating on my PCB. Could that be the problem - and if so, how should they be connected on a PCB? Pulled high or low?
Thanks for any help...
I have a simple circuit with an 08m2 flashing 3 LEDs in sequence. It works fine on breadboard, using a small programmer breakout I etched myself (with 22k and 10k resistors plus stereo jack) slotted into the breadboard, with the LEDs connected to the pins on the breakout board.
Then I tried etching a small PCB to transfer the circuit to it.
At this point, the circuit does this...
First LED come on for a few seconds. Then they start to flash in sequence. If I switch off and on, first LED lights for a few seconds and then they flash. Or sometimes mid sequence the first LED will come on for a few seconds and then the sequence kicks in again. Or first LED comes on and stays on indefinitely...
I have tried two copies of the etched board, and they both exhibit this behaviour. I have checked and rechecked every single connection using multimeter and continuity tester. I can't find any shorts or anything else odd.
The only thing I can think of is that maybe it's to do with having the serial in and serial out pins floating on my PCB. Could that be the problem - and if so, how should they be connected on a PCB? Pulled high or low?
Thanks for any help...