I made a PCB which consists of an attiny85 and an rf module (exact copy of syn/f115 module).
On my PCB I have 2 parallel capacitors connected to attiny85 "because I read that it's good to have them". I beg your pardon for that phrase but I'm not a pro. I'm just learning.
I am powering the rf module from attiny85 pin that it's not used for programming the attint85.
I can only flash the attiny85 if the capacitors of the rf module aren't soldered, otherwise I'm getting errors during uploading sketch. After flashing and solder them then everything works, I can even flash sketches!
So why first time a brand new attiny85 won't get flashed if everything is soldered on the board but then it can get flashed?
Just keep in mind it can get flashed after, but only for few times.. Then it failes on verification process and then it dies. I need to de solder, flash it alone and then solder it back and then I can Flash it few times again..
the schematic i used for the transmitter(transmitter works great), is from the manual of that f115 chip, is this one:
Only diferance is where C1 is, i have an other one parallel to this one,same value. So it is an exact copy of syn115 module.
Vdd is the output of my attiny85 PB3. this pin PB3 isn't used for programming the chip so i do not understand why i cannot flash it.
I can only upload sketches if i desolder C1 and the other capacitor that i added.. but then transmitter isn't working.. I do not want to have to desolder and resolder the capacitors everytime i need to flash my attiny85..
The schematic of attiny85 is very basic, i do not have access to it now. Only 2 parallel Capacitors Vcc-Gnd 10uF each. And PB3 connected to Vdd of syn115.
Only diferance is where C1 is, i have an other one parallel to this one,same value. So it is an exact copy of syn115 module.
If you made a custom PCB you should have schematics of that board. Post the schematics of your board!
In that schematics I cannot see an ATtiny. You described only the PB3 to Vdd connection. I would expect at least a GND connection.
PB3 is used in high voltage serial programming so it might be checked although the datasheet doesn't say anything about that.
