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Could not scan for EEPROM, Product: 24CW64X, 4-balls

Gabbie

Aug 1, 2018
2
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Aug 1, 2018
Messages
2
Hi Everyone!

I recently bought a few EEPROM of type 24CW64X ,4-balls. The data sheet is as shown here:

http://ww1.microchip.com/downloads/...ith Software Write Protection_DS20005772A.pdf

I have connected the 4 balls on this memory device, according to their supply voltage (Vcc), ground voltage (Vss), Serial data Pin( SDA) and serial clock input (SCL), to the Arduino Uno, and connected pull-up resistors of 2kOhms (as mentioned in the data sheet) to both the SDA and SCL.

However, when i tried scanning for this device using the code from this website:

https://playground.arduino.cc/Main/I2cScanner

, I usually get errors for some of the EEPROMs such as:
"No device found."

or errors such as:
"Unknown error at address 0x25
Unknown error at address 0x30
Unknown error at address 0x55"

I am thinking that this memory device may require me to first remove the write protect or to perhaps change the slave address first through the Hardware Address Register?

I am stuck now at this stage, and being a beginner in electronics and coding, it will be great if any one can provide help. Thank you very much!

-Gabriel
 

kellys_eye

Jun 25, 2010
5,138
Joined
Jun 25, 2010
Messages
5,138
Check section 3.3 of the data sheet for programming the HAR (Hardware Address Register) to establish the values necessary for I2C detection.

Without pre-establishing these settings the device will be 'random/unknown'.
 

Gabbie

Aug 1, 2018
2
Joined
Aug 1, 2018
Messages
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Thanks for your reply! I have went through the datasheet again, and on page 9, Table 3-2, it seems like there is a preset slave address of A2,A1,A0 = 0, 0, 0, which corresponds to 0x50 in hex. Do you think this slave address can be found by the I2C scanner code, or should I still establish the HAR settings first?

Also, do you have any tips on programming the HAR? It seems like on page 20 and 23, they did mention on the bits to be written for the HAR byte. However, they are not exactly clear on how to do it. Should I address the HAR byte by sending a transmission to it? Thanks!
 
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