I have a dev board for my attiny85. when connecting it to the computer I get "unknown USB device(device descriptor request failed)" although I have the needed drivers, so I thought of trying using my nodemcu. Tried connecting the SPI (to the nodemcu hmiso;hmosi;hcslk;hcs)and upload using "arduino as ISP" and compitable settings(https://www.hackster.io/arjun/programming-attiny85-with-arduino-uno-afb829). pressing "burn bootloadre" using this way gives me errors:

"avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x03


avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x03

Error while burning bootloader."


After changing a line(#define USE_OLD_STYLE_WIRING) in ArduinoISP (from example) the error code changed a bit and it shows up much faster:

"Arduino: 1.8.13 (Windows Store (Windows 10), Board: "ATtiny25/45/85, ATtiny85, Internal 8 MHz"

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x04

avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x30

avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x61

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x67

avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xc1

avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0xc4

avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0xc5

avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0xa1

avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0xcc

avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xe2

Error while burning bootloader."

Any help on how to use nodemcu to program attiny85 will be great thanks

  • how did you prevent reset of the NodeMcu? try a different pin then io15 for reset of target
    – Juraj
    Nov 6, 2020 at 13:08
  • Hi thanks for answering, first thing I tries was GPIO5 with no success :(
    – tal itshak
    Nov 6, 2020 at 15:00
  • how do you prevent auto-reset of the NodeMcu?
    – Juraj
    Nov 6, 2020 at 15:12
  • you mean by using a capacitor from RST to GND? I did try using a capacitor, although a 22uF one, did not work
    – tal itshak
    Nov 6, 2020 at 16:01
  • Using a 10 uF also did not work nor trying flashing the bootloader using the cmd
    – tal itshak
    Nov 8, 2020 at 21:05

1 Answer 1


Modifications to the ArduinoISP.ino sketch

I made the following changes to the ArduinoISP.ino file it exists in IDE version 1.8.13, and uploaded it to the NodeMCU board.

In short, I commented out (by way of #if 0) the heartbeat, err, etc LED related stuff. Not doing this causes the board to reset for reasons that would probably be apparent if I researched it, but I haven't and since I don't plan on using the LEDs and that you may not, I figured I would get this to you sooner.

I changed RESET to be SS which on NodeMCU is D8.

Why LED related code causes resets

... Out of curiosity I just went and looked at the ESP-12F and ESP8266EX datasheets. GPIO7, GPIO8, GPIO9 all go to the ESP-12F's SPI flash (program storage), so ostensibly monkeying with them interferes with the modules ability to keep executing from the SPI flash. They're not routed to NodeMCU pins, probably for that reason. So there's the answer to that.


@@ -70,7 +70,7 @@
 // The standard pin configuration.
-#define RESET     10 // Use pin 10 to reset the target rather than SS
+#define RESET     SS // Use pin 10 to reset the target rather than SS
 #define LED_HB    9
 #define LED_ERR   8
 #define LED_PMODE 7
@@ -216,15 +216,17 @@
 void setup() {

+#if 0
   pinMode(LED_PMODE, OUTPUT);
   pulse(LED_PMODE, 2);
   pinMode(LED_ERR, OUTPUT);
   pulse(LED_ERR, 2);
   pinMode(LED_HB, OUTPUT);
   pulse(LED_HB, 2);
@@ -276,6 +278,7 @@
 void loop(void) {
+#if 0
   // is pmode active?
   if (pmode) {
     digitalWrite(LED_PMODE, HIGH);
@@ -291,6 +294,7 @@
   // light the heartbeat LED
   if (SERIAL.available()) {

NodeMCU to ATTiny85 ISP Wiring

The board is wired to the ATTiny85 as follows:


On the NodeMCU you'll find all 6 of these together on the right.

Verifying AVRDUDE functioning

avrdude -P /dev/ttyUSB0 -c stk500v1 -b 19200 -p attiny85

Reading | ################################################## | 100% 0.02s

avrdude: Device signature = 0x1e930b (probably t85)

avrdude: safemode: Fuses OK (E:FF, H:DF, L:71)

avrdude done.  Thank you.

I've been playing with this chip, so don't be surprised that I don't have the same fuse values you have.

  • 1
    Thanks a lot! Commenting the LED parts in the code made the diffrence.
    – tal itshak
    Nov 11, 2020 at 13:51
  • Good deal. I'd considered just putting only that, but wanted to make it a little more complete. To be clear, changing the pin definitions for the leds to non-problematic pins would also work. I may edit it later to to suggest and, maybe add a picture of the wiring if I get around to making a clean picture.
    – timemage
    Nov 11, 2020 at 14:26

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