# connecting an LCD screen to the gps-rtk2 **URL:** \ **Category:** Development Boards\ **Created:** [October 9, 2020, 9:15am UTC](https://community.sparkfun.com/t/connecting-an-lcd-screen-to-the-gps-rtk2/40628 "2020-10-09T09:15:27Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![simon.ritchie](https://avatars.discourse-cdn.com/v4/letter/s/d07c76/32.png) [@simon.ritchie](https://community.sparkfun.com/u/simon.ritchie)\ **Post date:** [October 9, 2020, 9:15am UTC](https://community.sparkfun.com/t/connecting-an-lcd-screen-to-the-gps-rtk2/40628/1 "2020-10-09T09:15:27Z")
In the hookup guide [https://learn.sparkfun.com/tutorials/gp … okup-guide](https://learn.sparkfun.com/tutorials/gps-rtk2-hookup-guide), the section titled Setting the ZED-F9P as a Correction Source describes how to connect an LCD screen to the gps-rtk2. It gives the part number for the LCD and shows how to connect it, but that’s all. The picture in the guide shows the LCD displaying text, the position of the antenna. I’ve bought the same LCD and connected it to my board in the same way. When I switch on, the display lights up, so it’s working, but no text appears. I’m guessing that I have to set some config variables to make that happen, but which ones? ---
**Author:** ![TS-Chris](https://yyz1.discourse-cdn.com/sparkfun/user_avatar/community.sparkfun.com/ts-chris/32/6057_2.png) [@TS-Chris](https://community.sparkfun.com/u/TS-Chris)\ **Post date:** [October 9, 2020, 2:54pm UTC](https://community.sparkfun.com/t/connecting-an-lcd-screen-to-the-gps-rtk2/40628/2 "2020-10-09T14:54:26Z")
Hi Simon. You need a micro controller and software to make the LCD work. [[Example 4](https://github.com/sparkfun/SparkFun_Ublox_Arduino_Library/blob/master/examples/ZED-F9P/Example4_BaseWithLCD/Example4_BaseWithLCD.ino) in the Ublox ZED-F9P library will get you started.]([SparkFun\_Ublox\_Arduino\_Library/examples/ZED-F9P/Example4\_BaseWithLCD/Example4\_BaseWithLCD.ino at master · sparkfun/SparkFun\_Ublox\_Arduino\_Library · GitHub](https://github.com/sparkfun/SparkFun_Ublox_Arduino_Library/blob/master/examples/ZED-F9P/Example4_BaseWithLCD/Example4_BaseWithLCD.ino)) ---
**Author:** ![simon.ritchie](https://avatars.discourse-cdn.com/v4/letter/s/d07c76/32.png) [@simon.ritchie](https://community.sparkfun.com/u/simon.ritchie)\ **Post date:** [October 13, 2020, 9:58pm UTC](https://community.sparkfun.com/t/connecting-an-lcd-screen-to-the-gps-rtk2/40628/3 "2020-10-13T21:58:14Z")
Do you mean [https://github.com/sparkfun/SparkFun\_Ub … ixType.ino](https://github.com/sparkfun/SparkFun_Ublox_Arduino_Library/blob/master/examples/Example4_FixType/Example4_FixType.ino)? This just seems to read a position from the GPS device and write to the Arduino’s serial connection. However, the picture in the hookup guide shows the LCD board connected to the GPS device, not to the microcontroller. How does the data get from the controller to the LCD? Regards Simon ---
**Author:** ![TS-Brandon](https://avatars.discourse-cdn.com/v4/letter/t/cc9497/32.png) [@TS-Brandon](https://community.sparkfun.com/u/TS-Brandon)\ **Post date:** [October 13, 2020, 10:10pm UTC](https://community.sparkfun.com/t/connecting-an-lcd-screen-to-the-gps-rtk2/40628/4 "2020-10-13T22:10:05Z")
Are you referencing this picture: [https://cdn.sparkfun.com/r/600-600/asse … th\_LCD.jpg](https://cdn.sparkfun.com/r/600-600/assets/learn_tutorials/8/5/6/SparkFun_GPS-RTK2_Board_-_BaseStation_with_LCD.jpg)? If so, it is connected to the Microcontroller via the Qwiic I2C cables. With I2C, you can have multiple devices on the same ‘wire’ but can be spoken to individually. So the BlackBoard in that picture is really controlling and talking between the GPS and LCD. ---
**Author:** ![simon.ritchie](https://avatars.discourse-cdn.com/v4/letter/s/d07c76/32.png) [@simon.ritchie](https://community.sparkfun.com/u/simon.ritchie)\ **Post date:** [October 14, 2020, 7:54am UTC](https://community.sparkfun.com/t/connecting-an-lcd-screen-to-the-gps-rtk2/40628/5 "2020-10-14T07:54:04Z")
So the blackboard sends some text along the cable at the bottom of the picture, it passes through the GPS board and goes to the LCD via the cable at the top of the picture. Correct? My Microcontroller is a Raspberry Pi running software written in Go, so I need to understand the general principles. I can read the Arduino software but I can’t actually use it. Regards Simon ---
**Author:** ![TS-Brandon](https://avatars.discourse-cdn.com/v4/letter/t/cc9497/32.png) [@TS-Brandon](https://community.sparkfun.com/u/TS-Brandon)\ **Post date:** [October 14, 2020, 5:42pm UTC](https://community.sparkfun.com/t/connecting-an-lcd-screen-to-the-gps-rtk2/40628/6 "2020-10-14T17:42:52Z")
Correct. If you are new to I2C and how the communication protocol works then I would suggest reading through this tutorial: [https://learn.sparkfun.com/tutorials/i2 … 1578439588](https://learn.sparkfun.com/tutorials/i2c?_ga=2.99218718.1699804333.1602687561-2114068872.1578439588)