Thanks for looking at this. The example you provided has the DEBUG_UART transmitting only, which I don’t have an issue with. It’s the DEBUG_UART RECEIVER that breaks when the E-INK display is powered on.
I just checked the schematic of CY8CKIT-028-EPD and CY8CKIT-062-BLE.
I imagine that CY_EINK_RstHigh and CY_EINK_RstLow are flipping P5.
In CY8CKIT-062-BLE, UART_RX is P5, UART_TX is P5,
and UART_RTS is P5.
So if flipping P5 affects the UART, I think that the UART's hardware handshake is enabled.
Could you try disabling UART (DEBUG_UART)'s hadware handshake?
As usual, if I'm totally missing the point, I'm sorry.
I don’t have the RTS/CTS enabled. And it used to work just fine but stopped working. I went to an old version of software that was working and it doesn’t work. I purchased another board and it doesn’t work as well. There must be some sort of coupling.
On another note, I have a PWM connected to P9 and P9. The P9 toggled but the P9 stayed low. I then changed P9 to P9 and it toggles properly. They each had exactly the same configuration. Is there any reason that P9 wouldn’t toggle?
> I don’t have the RTS/CTS enabled.
> And it used to work just fine but stopped working.
I'm sorry for hearing that.
> I went to an old version of software that was working and it doesn’t work.
> I purchased another board and it doesn’t work as well.
> There must be some sort of coupling.
May be the change of PDL versions is affecting it.
> On another note, I have a PWM connected to P9 and P9.
> The P9 toggled but the P9 stayed low. I then changed P9 to P9 and it toggles properly.
> They each had exactly the same configuration. Is there any reason that P9 wouldn’t toggle?
In the schematic, P9 is used for TRACEDATA_0 and connection from P9_3 to J2_P9_3 is open (resistor is not placed)
So I hope that if you add a 0 ohm resistor at R131 P9_3 would work.
Looking at the Quick Start Guide, it appears that both DEBUG_UART:rx and E-INK display D0 and mapped to P5. Also, DEBUG_UART:tx and E-INK display D1 are mapped to P5. Am I misunderstanding this?
CY8CKIT-062-BLE Rev 15
CY8CKIT-028-EPD (E-INK DISPLAY SHIELD) REV 13
On my E-Ink Shield D0 and D1 are NC.
And 062-BLE D0 = P5_0 (UART_RX) and D1 = P5_1 (UART_TX)
But may be your version has different pin assignment.
If P5 and P5 are assigned to both UART and E-INK Data
your problem seems to be natural.
Could you check the version of your boards?
Although I'm still not quite sure if P5 / P5 are conflicting with EPD data,
but if it's the case and if you don't mind modifying the board,
I think that removing those resistors and assign UART to other pins, which are not taken by the EPD
and connect them using jumper wires to 5LP's P12/P12 will workaround the problem.
I have the same board revisions.
> I have the same board revisions.
If so, D0 and D1 of the EPD should be NC.
That's why I was assuming that D2, which is EPD_RST and also used for UART_CTS is causing the problem.
if the following line is called only once (or very few times)
displayDetected = Cy_EINK_Power(CY_EINK_ON);
Can you deinit and init UART after that line and see if it can workaround the problem?
The deinit/re-init after the display powers up doesn’t work.
> The deinit/re-init after the display powers up doesn’t work.
Thank you for your testing.
And I'm sorry that it did not help.
By any chance can you attach a project which can reproduce your problem?
Since your deinit/re-init did not work,
I'm wondering which is affected by the flipping of D2
PSoC 6's UART or PSoC 5LP (KitProg)'s USB-UART bridge.
Can you test the following?
(1) Attache a couple of Jumper wires at D0 and D1
(2) Run your project up to where UART stops working
(3) Connect a Terminal Program to the KitProg's COM
(4) Short D0 and D1
(5) Try typing something from the Terminal Program
If you see the echo back of what you are typing,
KitProg's UART is fine, otherwise KitProg's UART is in trouble with the D2 flip.
If the problem is happening at KitProg's UART, we can not do much from the PSoC 6 side.
May be, it will be the easiest to assign other pins to DEBUG_UART and attache a USB-Serial Converter to it.