My objective is to utilize an ir sensor to receive ir codes from a remote with an attiny on battery power. This design eventually will be sent off to be produced in a larger quantity. Prototype works fine on larger arduinos of course. On the tiny, the same ir codes didn't work reliably, I figure the clock is slightly off so I'm trying to re evaluate what ir codes the tiny is seeing.
So I installed the latest tiny core, was able to read serial output from the attiny85 through the serial monitor by uploading an empty sketch to my UNO, and connecting UNO reset to ground.
My problem comes when I try to connect an IR receiver to the attiny, the serial output stops. Any idea what could cause this?
Side question - Is it possible to program the attiny85 with components attached? I only seem to be able to program the attiny if no components are attached... I hope to later be able to get my design on pcb and still be able to make updates to the code if needed
Im only using the uno as the tiny programmer and to read serial data.... Ir receiver connected on pin 2 of the tiny, the shared ground of the tiny+uno, and the 5v to the tiny from the uno.
When you say it stops when you connected the IR receiver, do you mean when you physically connected it, or when you added code that interacts with it? In the latter case, we need to see your code.
Wow thanks mrburnette, I had swapped the 5v with the reset. Shame on me for using same colored wires.
My other question still stands, though. Is it possible to program the attiny with components attached? I need a way to update the chips when I get the fully assembled circuits produced. When the IR sensor is attached and I upload code, I get:
avrdude: verification error, first mismatch at byte 0x0000
0x00 != 0x10
avrdude: verification error; content mismatch
I mean I guess I could include a bridge/jumper on the PCB to cut off interfering components but I would prefer not to...
Unless there is a reason not to, the simplest solution is to move the green connection from (physical) pin 7 to pin 4 and leave pins 5, 6, and 7 unconnected.
If you cannot move the connection, a series resistor is the next best choice. Anything above 250 ohms will protect the processor and programmer. You may need a higher resistance to protect the IR receiver. Bear in mind, the higher the resistance the more adversely the signal is effected. If necessary a lower bit rate can be used. (I used 51kΩ resistors to isolate a TLC5940.) If you do use a series resistor it is important that the programmer not have series resistors and that the programmer is connected to the processor side.
The third choice is to use a FET / bus-switch to isolate the processor during programming. If you reach this option I can recommend something (it will be a surface-mount chip).
