# EEPROM is delivered in empty state ## Problem environment The EEPROM part U6/U7 is connected to the Raspberry Pi secondary I2C interfaces, used for identifying the hardware attached on top of the host computer. ## Steps to reproduce 1. Refer to the schematic 1. Study the circuits around U6/U7 ## Expected result The EEPROM connected to each device contains data uniquely identifying it as a Sendcomm. ## Actual result The EEPROM is not prepared, and contains no data. ## Workaround Assume the user will follow documentation to enable the UART without choosing login. ## Resources https://github.com/raspberrypi/hats/ https://www.raspberrypi.org/documentation/configuration/config-txt/boot.md https://www.raspberrypi.org/forums/viewtopic.php?f=107&t=265631 https://www.raspberrypi.org/blog/introducing-raspberry-pi-hats/ https://magpi.raspberrypi.org/articles/make-your-own-hat/ https://www.raspberrypi.org/documentation/configuration/uart.md https://www.raspberrypi.org/forums/viewtopic.php?t=108134 https://github.com/raspberrypi/hats/blob/master/eeprom-format.md https://github.com/raspberrypi/hats/tree/master/eepromutils ## Severity level This is **low priority** because project requirements do not mandate hardware identification.

$ echo 'dtoverlay=miniuart-bt' >>/boot/config.txt
$ reboot
$ screen /dev/ttyAMA0 115200

$ echo 'enable_uart=1' >>/boot/config.txt
$ reboot
$ screen /dev/ttyS0 115200

Regardless of **EEPROM contents**, it may be needed to direct the user to modify: ``` $ echo 'dtoverlay=miniuart-bt' >>/boot/config.txt $ reboot $ screen /dev/ttyAMA0 115200 ``` ...or ``` $ echo 'enable_uart=1' >>/boot/config.txt $ reboot $ screen /dev/ttyS0 115200 ```

Although UART preconfiguration is not possible, the EEPROM device is delivered preprogrammed with a product suitable data structure as committed in 4f9180b.