I'm not sure about it. The schematic seems different from PCB image. Anyway you can try connect directly and if the backlight has low brightness so you can make the changes above.
Yes, but you should make the changes explained here.
Moreover you have to edit the code to make the menu fill all the screen. All versions modified by users available on forum for 800x480 screen are outdated.
Hi! I told above: The solution could be bypass the ULN and change on code LOW to HIGH and HIGH to LOW. But I'm not sure if PCF can manage the current of all relays. If the circuit is working as I told above to prevent damage PCF I think that ULN could be replaced by a PNP transistor array and TD6238...
You should find a module with a PCF8575TS instead PCF8575C. Ferduino Mega and blue module has TS type. Should have some difference betweem TS and C type.
If you can't find this type can buy only the IC and replace on red module.
Hi! Merry christmas for all! For some reason this module is not working as OUTPUT just as INPUT. You can notice that relay is just turned on when a LOW command is sent. The solution could be bypass the ULN and change on code LOW to HIGH and HIGH to LOW. But I'm not sure if PCF can manage the current...
Gio, pictures and texts should be more useful. This video has bad quality (480p) and it's very short. Moreover I don't know your PCB. When the multimeter is showing negative voltage is because the polarity is inverted. You should swap probes positions. BTW, making videos in landscape is always the b...
With HIGH pins with both ULN and without it between 1-8 and GND (9) it measures 0 V Try measure the voltage directly over the IC (PCF8575) between P00 (pin 4) and GND if it has the same result the module is not working or Arduino is not communicating with PCF correctly. https://www.ferduino.com/for...
Hi! Two mistakes here. Between pins 1-8 and 5V measures 0 V I did not told to measure in this way. Basically you are measuring between 5 V and 5 V, it won't give any voltage obviously because there's no potential difference. What I told was: measure the voltage between pins 1-8 on socket and GND htt...
The headers on PCF module seems poorly soldered here: https://www.ferduino.com/forum/gallery/image.php?album_id=53&image_id=579 Can you remove the ULN from socket and measure the voltage between pins 1-8 on socket and GND with PCF signal HIGH? It should be around 5 v. After can you measure the v...
ULN can't be used with HIGH level trigger relay board. But I don't think it's your case because your relay board is LOW level trigger as shown here . https://www.ferduino.com/forum/gallery/image.php?album_id=53&image_id=632 Here you told me that the relays are activated when pins 1 to 16 are con...