I want my weatherstation to be connected wirelessly to internet to fetch weather data, time info, symbols etc. One of the cheapest option these days is to use a ESP8266. Originally I planned to use it only as a serial wifi device for Arduino. Moving small abouts of (structured) data such as forecast, time etc. from ESP8266 to Arduino is easy. But what about images? It seems to be easy to download images using ESP8266, such as Daniel Eichhorn have done in his ESP8266 Weather Station Color. But how to transfer images from 8622 to the Arduino? Common external flash or SDcard ? Serial ? I really don’t know. So, what if I can use the ESP8266 for everything and just ditch the Arduino? After all, the ESP8266 is a capable processor.
First time I saw the graphics capabilities of FT800 was on the Gameduino2. From then I’ve wondered if FT800 could be used as graphics controller in my weatherstation project.
Due to limited resolution it could only be used for LCDs up to 5″. Since then, the FT81x series of controllers have been released. They support higher resolutions and allows for typical 7″ displays. In the meantime I’ve also experimented with capacitive touch panels. I find them so much better that the resistive ones.
I’ve really liked the FT80x series of graphics chips, also called EVE. My main concern was that they only supported up to 512×512 pixels. That limitation prevented me from using it for 7″ displays. However, a few weeks ago the released a new generation consisting of four different versions: FT810, FT811, FT812 and FT813 ICs Among several updated features, they now support up to 800×600 pixels. Perfect match for 7″ displays. You can read more about it in the Press release.
A much cheaper alternative is i.e. the RA8875 based 5″ from BuyDisplay. It costs $35. Half the price. You can also buy separate touch panel to put on your own display for $8.50. The problem is that they use a Silead GSL1680 touch controller which is a bit tricky when it comes to writing drivers for it. Among other things it requires special firmware to work. I just gave up on it. That was until Tomek started the Has-anyone-tried-running-the-GSL16880-capacitive-touchscreen-controller-with-Teensy3 thread over at PJRC(Teensy) forum. January 14th, wolfmanjm got the buydisplay GSL1680 based board up’n running with a STM32L100 discovery board. He posted a video on youtube. After that it was tested on Teensy, and finally CosR1 managed to get it up’n running on an XMEGA AVR.
I just revisited Andy’s workshop after reading about his FPGA Sprite graphics accelerator. The FPGA article might not be direct relevant for my weatherstation project. However, there are a lot of other interesting articles there i.e. about reverse engineering of phone displays such as Vivaz and LG KF700. Might be worth a look.
I’ve tried several LCD screens for “hobbyists”. Initially they look good, but as soon as you look at them from the side, the colors typically get washed out. This is the same problem TVs, PC screens and mobile phones had 2-3 years ago. Why haven’t the progress in those areas “leaked” into the hobbyist marked ? Could it be price ? In order to find the “best” screen I’ve created a colorbar test that currently works for some of the different LCDs/controllers out there. The goal is to test several LCDs, take pictures from different angles and post them at my blog. If you have suggestions for what to test, or have links to relevant info, please leave a comment.
The colorbar test can be found in github. The LCDs currently supported by the code are based on FT800, RA8875, and “UTFT” controllers.
Today I came across a post from 2012 describing a weatherstation based on Kindle. If I understand correctly, an image is created on a separate server and a small script running on the Kindle fetches the image and displays it. I similar idea uses a hacked kobo with on-board code.
Got my new 3.5″ IPS display today. It was delivered much quicker than I’m used to. I ordered 11.feb. and got it 25.feb (to Norway). That’s a new record. I bought in on ebay (from Coldtears Electronics Store) mainly because they claim that this LCD has “full viewing angle”.
I’ve looked at it briefly, and it actually seems to have pretty good viewing angle from all sides.
Info on the sellers page describes how to make it work with Henning Karlsens UTFT library with some extra software. In fact it is easier. V2.71 of the library supports the LCD out of the box. In the example UTFT_Demo_480x320, just replace CTE32HR with CTE35IPS in line 22. I tested with UTFT V2.74. The extra library can be added to support i.e. extra fonts. I didn’t get that to work. Could be due to wrong library or solder pads ? I’ll try to find out later.
Note that the unit has a protective film on top of the display even though it it not easy to see. At first I thought I had got a used sample. I had not. After removing the film it looks great.
From what I’ve seen until now, and the quick response from the seller, I wouldn’t hesitate buying from Coldtears again.
I’ve just got my RA8875 based 7″ LCD up’n running together with Arduino UNO. After a bit of struggling with removing SMD resistors, “jumpers”, bad connections etc. I first got it working with the example files for the Adafruit RA8875 Driver Board.
I then started investigating the capacitive touch screen controller (FT5206). After reading the documentation and some experimenting, I finally managed to write a driver for 5 point multitouch. I’ve pushed the arduino code to github for those who are interrested.