7 inch display: Which UCM module?

I am going to start a project using the 7 inch display sold by GHI, along with a UCM module. I have the UC5500 with wifi, and I will get the dev board even though I have the smaller breakout already. The application will monitor a water system at my house, including water well levels, water tanks levels, maybe water flows using a separate micro counting pulses, most of the stuff is simple digital inputs or analogue 4-20ma stuff. I want to store data about the system, probably using an sd, no need to put it in the cloud.

The display will be a place for the user to interact with the program, view water flows and water levels, configure the system (will have the ability to fill rainwater tanks using the domestic water supply etc, the system has a reverse osmosis system for making fresh water from the brackish well supply).

So I am wondering if I am better of getting the G400 module, rather than using the 5500 module I already have, does anyone have any experience using the 7 inch display with either module performance wise? I can use either wifi, or hardwired network connection from the display unit, mounted in the house, to the water system located about 100 feet away in a separate building. In the separate building, I can use another micro of some kind connected directly to the sensors and recording data, perhaps polled by the main system at the house, and recorded to SD. The only thing that needs to be “real time” would be the hall effect flow sensors, and they could be tasked to their own dedicated micros that would just count flows and communicate with the main micro using I2C or serial.

Any comments on appropriate hardware would be appreciated, thanks!


Why use G400 instead? UC5550 is new and recommended for all new designs. If you are judging this based on the clock speed, G400 is ARM9 and UC5550 is Cortex-M7. Meaning UC5550 is as fast if not faster.

Please share pictures of your project as you build. It is always exciting to see what everyone is inventing.

That’s great, thanks Gus. Looks like the G400 is back-ordered anyways!

As the UC5550 has a CAN bus, consider using that to connect your devices together. Making nodes with CAN is easy and cheap now too. CAN removes the need to poll the data and you can connect them all on the same bus. No need to worry about collisions etc. CAN does it all for you. You sensors just send data when they want to and the CAN bus protocol handles the bus for you. It will also work well over your 100ft distance and even further if need be.


Good idea. I completely forgot about CAN.

Hi Dave, I am just using a standard ethernet twisted pair, this can be used fine for CAN? I’ll read up on CAN bus, never used it… I was using an I2C bus extender with mixed results in an earlier iteration with a Picaxe… looking for something a bit more reliable. Was going to use http or something between the micros, but CAN might be easier!


RS485 is another option.

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Same as you would with RS485, you need a pair for the RS485 pair and a ground so 3 wires in total.

Justin’s idea for RS485 would work but requires a bit more work as you need to have a master and poll each device. CAN requires no polling.

For reference, I ran CAN many years ago (over 25) on a 1000m ROV umbilical twisted pair. I used 10Kbps data rate and the pair came as a quad bundle with 2 pairs and a common ground. Worked perfectly.

I am using UC5550 with the UD700. I also am using CAN to communicate with a single device. The system is designed to use the CAN interface as a free running process within an idle loop. It results in dozens of request/response per second.
I am using many icons and fonts for the ud700. And have had no issues with the hardware: the UC5550 has plenty of power to do what you need. (it will spend most of the time in an idle state)

Another communication alternative is using the NRF24 radio. I have implemented a system similar to yours with an Arduino Uno driving a radio network of Arduino Nanos. Each of the Nanos interfaces with several sensors, ie temperature, humidity, light, flame, IR presence, distance, water level, relays etc. ( It even interfaces to the X10 system for house control) To implement a similar system with the UC5550/UD700 should be straight forward and there are many examples of drivers in the Arduino community.

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