# GC9A01\_LTSM library support
**URL:** https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038
**Category:** SDK
**Tags:** rtl8735b
**Created:** [September 2, 2026, 1:02pm UTC](https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038 "2026-09-02T13:02:21Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@rkuo2000](https://forum.amebaiot.com/u/rkuo2000)
#### Post date: [September 2, 2026, 1:02pm UTC](https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038/1 "2026-09-02T13:02:21Z")
Application : AI Robot , AI Watch
EVB : AMB82-mini
Peripheral : GC9A01 (a round TFTLCD)
Library : [GC9A01\_LTSM](https://github.com/gavinlyonsrepo/GC9A01_LTSM)
Symptoms : Failed to compile all examples.
---
### Author:  [@system](https://forum.amebaiot.com/u/system)
#### Post date: [September 2, 2026, 1:02pm UTC](https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038/2 "2026-09-02T13:02:23Z")
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### Author:  [@KevinKL](https://forum.amebaiot.com/u/KevinKL)
#### Post date: [September 3, 2026, 8:16am UTC](https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038/3 "2026-09-03T08:16:22Z")
Hi @rkuo2000 ,
Please try again with the updated patch for Ameba SPI library. Thank you.
[SPI\_patch\_030926.zip](https://forum.amebaiot.com/uploads/short-url/ovJhVwZeZwKqL5TImzPmL7SkBEQ.zip) (4.0 KB)
---
### Author:  [@rkuo2000](https://forum.amebaiot.com/u/rkuo2000)
#### Post date: [September 3, 2026, 9:27am UTC](https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038/4 "2026-09-03T09:27:17Z")
example code : [GC9A01\_HELLO\_WORLD.ino](https://github.com/rkuo2000/EdgeAI-AMB82mini/blob/main/Arduino/AMB82-mini/GC9A01_HELLO_WORLD/GC9A01_HELLO_WORLD.ino "GC9A01\_HELLO\_WORLD.ino")
compiled OK, but failed to run (with/without connecting GC9A01)
== Rtl8735b IoT Platform ==
[Normal mode]
BootFromNORFlash
[Start Boot ROM…]
=== Load PARTBL ===
=== Load Done ===
=== Load ISP\_IQ ===
[fcs chk pass]
ISP\_IQ @ 0x8461080, 0x2ff80, 0x0
mfcs\_data version 0x00010001
fcs\_data version 0x00010101
=== Process ISP\_IQ ===
=== Load Done ===
=== Load BL ===
[Image Start Table @ 0x18200]
=== Load Done ===
== Boot Loader ==
Aug 31 2026:12:40:36
=== Load FCS Para ===
=== Load Done ===
[crc pass]
=== Load ISP\_IQ Sensor ===
ISP\_IQ @ 0x8461080, 0x2ff80
=== Process ISP\_IQ ===
=== Load Done ===
=== Load FW1 ===
FW\_ISP\_IQ @ 0x8061080, 0x31f80
=== Process FW\_ISP\_IQ ===
DRAM\_TYPE is DDR2 128MB.
ddr\_freq = 533
VOE flash @ 0x8093080, 0x82f80
FCS KM\_status 0x00002081 err 0x0000200a
Wait KM fcs done 0 us
FCS TM\_status 0x003f0000
store fcs data for application
It don’t do the sensor initial process
RAM TM\_STATUS 0x00bf1208 err 0x00001208
read fcs\_status 0x000000bf
read fcs\_status 0x000000bf
=== Process VOE IMG ===
[Image Start Table @ 0x20106200]
RAM Load @ 0x8116100-\>0x20106200, 0x572c
DDR Load @ 0x811c080-\>0x70100000, 0x1a4b8
=== FW Load Done ===
Boot Loader \<==
== RAM Start ==
Build @ 12:30:26, Aug 31 2026
$8735b\>
[MISC Err]Pin 4[4] is conflicted
[MISC Err]It’s configured as GPIO now.
[MISC Err]It’s using by peripheral F0000000
[SSI Err]PIN 84 cannot be registered.
[SSI Err][31mspi\_format(): SPI 0 init fails.
[0m
[SSI Err]Please initialize SPI format first!
[SSI Err]Please initialize SPI format first!
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### Author:  [@rkuo2000](https://forum.amebaiot.com/u/rkuo2000)
#### Post date: [September 3, 2026, 11:13am UTC](https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038/5 "2026-09-03T11:13:11Z")
I fixed it without SPI\_SS, replaced as follows :
#define TFT\_DC 4
#define TFT\_CS 5
Looking forward to the fix for using SPI\_SS !!!
* * *
Here’s the fixed libraries .zip :
[GC9A01\_LTSM (revised examples)](https://github.com/rkuo2000/EdgeAI-AMB82mini/blob/main/libraries/GC9A01_LTSM.zip)
[display16\_LTSM (revised display16\_graphics\_LTSM.hpp)](https://github.com/rkuo2000/EdgeAI-AMB82mini/blob/main/libraries/display16_LTSM.zip)
examples/FRAME\_BUFFER failed to compiled (240x240x2 = 115,200 bytes required)
---
### Author:  [@rkuo2000](https://forum.amebaiot.com/u/rkuo2000)
#### Post date: [September 4, 2026, 2:02pm UTC](https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038/6 "2026-09-04T14:02:19Z")
Hi, @KevinKL :
I would still like to know why SPI\_SS can not be used with GC9A01\_LTSM library.
Your answer will be very appreciated !
---
### Author:  [@KevinKL](https://forum.amebaiot.com/u/KevinKL)
#### Post date: [September 7, 2026, 7:01am UTC](https://forum.amebaiot.com/t/gc9a01-ltsm-library-support/5038/7 "2026-09-07T07:01:02Z")
Hi @rkuo2000 ,
The GC9A01 library drives SPI\_SS manually as GPIO, while `SPI.begin()` tries to hand it to the MBED SPI controller as hardware chip‑select. For AmebaPro2 usage, kindly move the software CS init into the IF statement where hardware SPI is not used in `GC9A01_LTSM.cpp`
```auto
/*!
@brief init routine for GC9A01 controller
*/
void GC9A01_LTSM::TFTGC9A01Initialize()
{
if (_resetPinOn == true) {
TFTResetPIN();
}
DISPLAY16_DC_SetDigitalOutput;
DISPLAY16_DC_SetLow;
if (_hardwareSPI == false)
{
DISPLAY16_SCLK_SetDigitalOutput;
DISPLAY16_SDATA_SetDigitalOutput;
DISPLAY16_SCLK_SetLow;
DISPLAY16_SDATA_SetLow;
DISPLAY16_CS_SetDigitalOutput;
DISPLAY16_CS_SetHigh;
}else{
TFTHWSPIInitialize();
}
cmdInitSequence();
TFTsetRotation(Degrees_0);
}
```
Thank you.