Thursday, October 8, 2020

EPROM programmer -1-

I have several old UV erasable EPROMs that i want to use.
The UV EPROM ereaser orderd on AliExpress for using the EPROMS came sooner than expected. Now i also have received the PCB that i designed for the programmer and soldered some components on it.
For the programmer i wanted to use an Arduino and an external power supply for the programming voltage. The datalines will be directly connected to Arduino pins. For the address bus using a counter (or bigger an Arduino with more pins) would be the most easy solution. I want also to read data and select addresses without the need to count. In this first test circuit i want to use an Arduino Uno and a shift register to output the address.

As the PCB had some open space and there where also some unused lines from the Arduino and the shift register. I decided to add some useful (optional) bonus items on the PCB.

  • Pushbuttons (reset and an extra)
  • Leds
  • Buzzer
  • Voltage divider with two resistors to measure the programming voltage with an Arduino analog input port.
  • EEPROM (additional storage)
    Having an EEPROM on a UV EPROM board is perhaps a little confusing. It think it can be a valuable add on. Use cases can be; using the EPROM programmer as stand alone device to write the same program to several EPROMs, reading several EPROMS to the EEPROM for later investigation, comparing EPROMs, creating an EPROM emulator etc.


The first item i want to test on this PCB is the EEPROM. I hope soon on my blog will appear a post about this.
Testing of the UV EPROM i want to do after having more (programming) experience with the shift registers.
A project currently in progress is a special Arduino shield PCB to test and play with shift registers (and leds) This is a separate project i want to do before real EPROM programming. I ordered my EPROM programmer PCB at JLCPCB with the cheapest (slow) shipping service together with some other PCBs including the shift register test shield. With JLCBP (and some other PCB manufacturers) you currently get multiple PCBs for a very low price.

A project i want to do is a EEPROM test shield. I already designed this test shield however first i want to test my EEPROMs (using this EPROM shield) before ordering the EEPROM test shield.

There are also some other finished projects i want to publish on my blog. I hope you visit by blog again soon, and by that time there is also a post about my first EEPROM test results. 

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