Ricoh SP C250DN (Toner page couter reset) follow up

As described in an earlier Post, I hacked the Ricoh toner cartridge page counter in order to be able to refill them. Today I finally got around to draw a small box-shaped enclosure with four small pogo pins as the connecting element between the MCU and the cartridge. Because the flashing process does require external power, I added a standard USB-cable to connect to any 5V supply available. This really is handy, because the printer's USB port does also work just fine. As far as the circuit goes nothing really has changed. I added a 3mm yellow led to light up while flashing of the cartridge is in progress. In addition it does flash continuously on and off, if writing or reading back has failed. The Software is slowed down a lot to ensure good physical connection and a stable state inside of the cartridge's IC. Using the device works as follows:

1. - Attach the device to a power supply
2. - Align the device with the cartridge 
3. - Wait for the yellow led to light up
4. - Wait until the led goes off
5. - done! If the led does flash instead of continuously off, start from step one again.

The finished "product"

The advantage of using pogo pins -> perfect contact for each pin!