May 08, 2021 16:58:00

Introducing a fierce man who created a kit that can hack a dishwasher and reduce detergent costs by 98%

DekuNukem , a hardware enthusiast who was dissatisfied with the high cost of dishwasher detergent cartridges, created a kit that hacks detergent cartridges and cuts costs by 98%, and explains how to do it. ..

GitHub --dekuNukem / bob_cassette_rewinder: Renew and Refill Bob Cassettes for 98% Cost Saving!
https://github.com/dekuNukem/bob_cassette_rewinder

dekuNukem got a small household dishwasher ' Bob '.

Bob uses a special detergent cartridge '

Bob cassette ' as a detergent. The Bob cassette is equipped with a chip that records the 'remaining usable times', and Bob reads the chip data and displays the 'remaining usable times' on the monitor located at the top of the aircraft. I have.

According to dekuNukem, Bob cassettes can be used 30 times per cartridge, costing 67 cents per cartridge and $ 242 a year for daily use. thing. Feeling that the cost of the detergent was too high, deku Nukm came up with the idea of reducing the cost by refilling the Bob cassette with a commercial detergent.

However, Bob reads the 'remaining usable times' from the chip mounted on the Bob cassette, so even if the detergent is refilled, it becomes unusable when the 'remaining usable times' reaches 0 times. Therefore, dekuNukem decided to analyze the chip mounted on the Bob cassette and rewrite the 'remaining usable number of times'.

First, dekuNukem melted the plastic with a soldering iron and took out the chip mounted on the Bob cassette.

The tip looks like this.

'24C02 EEPROM ' is used as the non-volatile memory.

dekuNukem attached the removed chip

to a board created by another project and read the data stored in the 24C02 EEPROM.

The following shows the data stored in the 24C02 EEPROM when the 'remaining usable count' of the Bob cassette is 26 times (top) and 25 times (bottom). Since the only difference between the two is the part that changes from '4A ' to ' 49 ' surrounded by a red frame, dekuNukem predicted that 'remaining usable count' is recorded in this part. ..

Mr. dekuNukem recorded '4A' in hexadecimal when the 'remaining usable count' was 26 times, and '49' when it was 25 times, so when the remaining usable count was 30 times, it was '4E'. Is recorded, and it is predicted that the numerical value will decrease one by one from there. In order to make Bob recognize 'remaining usable times' as 15 times, I entered '3F' in the relevant part and connected to Bob. As a result, contrary to Mr. dekuNukem's expectation, the 'remaining usable count' was displayed as 111 times on the screen.

After that, dekuNukem, with the help of the community, revealed that the 'remaining usable count' is recorded as shown in the table below. The table shows the 'remaining usable count' on the left side and the corresponding hexadecimal number on the right side. Now, by entering '4E' in the relevant part, Bob will be made to recognize that 'a new Bob cassette has been installed'.

Deku Nukm, who solved the problem of 'remaining usable times', searched for a concentrated detergent for refilling by checking the ingredient list on the Internet.

As a result, dekuNukem discovered a super-discount detergent that can wash dishes for 1.1 cents (about 1.2 yen) each time. With this detergent, you can save more than 98% from Bob cassette, which costs 73 yen each time.

If you get a cheap detergent, use a syringe to inject it into an empty Bob cassette and rewrite the data ...

It can be recognized as a new Bob cassette. With this, dekuNukem has succeeded in reducing costs by as much as 98%.

However, this method requires the tip to be removed from the cartridge to reset the 'remaining usable count' each time the detergent is refilled. Therefore, dekuNukem designed a

dedicated board 'Bob Rewinder ' that rewrites the 'remaining usable times'.

How to use Bob Rewinder is like this. Simply connect the tip of the cartridge to the slot on the bottom of Bob Rewinder, connect it to the power supply with a USB cable, and press the 'RENEW' button to reset the 'remaining usable count'.

dekuNukem sells a kit that includes a designed Bob Rewinder, Bob cassette, and syringe. The price is 3113 yen, and the shipping fee to Japan is 725 yen.

In addition, dekuNukem publishes Bob Rewinder's design data etc. on his GitHub repository .