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Edouard Lafargue let us republish his demonstration of a Noritake GU140x32-7002 Serial VFD screen (may prompt about a secure certificate).
The Noritake VFD used here is a “Show and Tell” 140×32 semi-graphical VFD. This display has the big advantage of being able to display graphics and manage so-called ’user windows’, making it a good choice for stepping up from standard text-based LCDs or VFDs towards a more graphical approach.
This tutorial first shows how to interface with the device using async mode, and then how to use a simple python script to display GIF black and white images on the display.
Mike Donovan suggests that a USB version of Zibri’s Force Trainer interface hack could be done with a Bus Pirate. Substitute the MAX RS232 serial converter with a Bus Pirate in UART mode configured for 57600, 8/N/1 : “call it Bus Pirate Mind-Reading Mode”. View output in the terminal, or start the transparent UART bridge (macro 1) to interface with Zibri’s software.
Thanks for the tip!
The logic analyzer output above (top continues on the bottom) shows the Bus Pirate I2C address scan function. The Bus Pirate sends a DS1307 I2C read address. After the DS1307 ACKnowledges the address (bit 9), it immediately starts sending data to the Bus Pirate and ignores the I2C STOP sequence sent by the address scanner. This caused extra I2C addresses to appear at random.
This is the purpose of the I2C NACK bit that concludes a transfer from the slave IC to the master device. If the master ACKs the last byte and then attempts a STOP condition, the slave might put a 0 on the data line that blocks the STOP condition. If the master NACKs the last byte then the slave IC gives up and everybody exits cleanly.
Read more about this issue here, updates will be in the nightly compiles in a few days.