Attiny85 and HW-260 vs Digispark

Using Arduino Avrdude, stk500, Bootloader issues
1

I've run sketches on the Digispark USB board with Attiny85 using the libusb-win32 driver. Just got the HW-260 Attiny socketed board which appears to be the same as the Digispark. The two schematics look the same too.

However I can's load any scripts to the HW-260 with usb cable after adding the bootloader to the Attiny85 (with an Uno). Communication isn't right because the libusb driver doesn't appear in Device Mgr.

Next I connected the a FTDI breakout board to HW-260 ICSP header (5V, grd, tx, rx and dtr). This time Arduino recognized FTDI on com4 but still no libusb driver.

Hoping someone can explain what I'm not understanding. What's on the Digispark that's not on the HW-260+Attiny.

Digispark schematic

digispark
digispark987×589 56.4 KB

HW-260 schematic
hw-260 schematic

*** Note fixed my error of naming HW-280 by mistake. Changed the origin post to HW-260. ***

2

Is it HW-260 or HW-280?

3

Sorry I had 280 on the brain. You are right it is the 260.

4

D3 looks reversed to me in the Digispark board schematic. I don't understand how that thing gets powered via USB.

What core did you use to burn the bootloader? Attinycore or another?

5

Yes, I used the Attiny85 bootloader from the IDE.

6

I follow these steps:
1. Using an AVR Programmer, I read the Fuse Settings of the ATiny85 MCU located on the Digispark Attiny85 Board and recoder them. How?

Solder 8 header pins on the Digispark Board. Take an 8-pin socket and solder 8 jumpers. Connect the female ends of the jumpers on the pins of the Digispark Board. After that place the socket on the AVR Programmer.

2. I read the whole flash content (the Bootloader) of the ATtiny85 MCU of the Digispark Board.

3. I place my fresh ATtint85 chip on the AVR Programmer.
4. I set/write the Fuse Settings of Step-1.
5. I copy/write the Bootloader of Step-2.
6. I take out the MCU from the AVR Programmer and place it into the empty socket of HW-260 Dev Board.

7. I use HW-260 Dev Board and develop my product/project.
8. I take out the MCU from the HW-260 Board and place it on the AVR programmer.
9. I lock the memory Lock Bits as I need.
10. I take out the MCU from the AVR Programmer and place it on the PCB of my product/project.
11. The project is done.

1 Like
7

Thank you so much for sharing. I've read many posts and this is the first to copy Digispark mcu and copy to a new part.

Will give it a try and report back.

8

You have to set the Fuse Bits correctly; otherwise, the Boorloader will not work.

For your record:
1. Fuse Bits for the ATtiny85 of Digispark Board (I read sometimes ago).

EF(Extended Fuse Byte)  HF(High Fuse Byte) LB(Low Fuse Byte) LB(Memory Lock Byte)
FE                      DD                 E1                FF

External RESET/-pin is active
Operating Frequency is 16 MHz obtained from internal 8 MHz using PLL

2. I also read and saved somewhere the Bootloader which I cannot find now; otherwsie, I could attach that file for you.

9

Is the bootloader you are referring the micronucleus or a special Digispark one.

10

I don't know exactly where this bootloader could be found. I have got it for myself by reading it from the onboard ATtiny85 MCU of the following Digispark ATtiny85 Dev Board.
DigisparkAttiny85Board

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