04-18-2023, 10:09 PM
(This post was last modified: 04-18-2023, 10:14 PM by victorclaessen.)
Ok, I tested it with that firmware. The board does not echo anything back unless I pull down pin2 on the SP485EE (via 2k resistor).
Diving deeper into the datasheets, I can see that the MAX13487E that is shown on the board in the Kincony documentation has an intelligent feature to disable receiver output whenever the chip is sending. I quote from the datasheet: "Drive RE low to enable the RO. Drive RE high to let the AutoDirection circuit control the receiver."
However, my rev1.4 board does not have a MAX13487E but rather an SP485EE, which does not have an AutoDirection circuit according to its datasheet, and the RE has to be driven manually, which is not implemented on this board!
Did I buy a counterfeit Kincony board???
Diving deeper into the datasheets, I can see that the MAX13487E that is shown on the board in the Kincony documentation has an intelligent feature to disable receiver output whenever the chip is sending. I quote from the datasheet: "Drive RE low to enable the RO. Drive RE high to let the AutoDirection circuit control the receiver."
However, my rev1.4 board does not have a MAX13487E but rather an SP485EE, which does not have an AutoDirection circuit according to its datasheet, and the RE has to be driven manually, which is not implemented on this board!
Did I buy a counterfeit Kincony board???