Simple example for uc8151 doesn't build, am I doing something wrong?

[haswalt]

I'vejust installed tinygo, configured GoLand using the plugin (also tried VSCode) but I get errors when trying to build one of the examples, specifically the uc8151 example.

I've tried testing by my on terminal and using the latest docker image and I get the same error:

tinygo build -target=pico-w ./main.go
go: downloading tinygo.org/x/drivers v0.32.0
# command-line-arguments
main.go:20:22: undefined: machine.EPD_SCK_PIN
main.go:21:22: undefined: machine.EPD_SDO_PIN
main.go:24:45: undefined: machine.EPD_CS_PIN
main.go:24:65: undefined: machine.EPD_DC_PIN
main.go:24:85: undefined: machine.EPD_RESET_PIN
main.go:24:108: undefined: machine.EPD_BUSY_PIN
make: *** [build] Error 1

Checking tinygo info -target=pico-w:

LLVM triple:       thumbv6m-unknown-unknown-eabi
GOOS:              linux
GOARCH:            arm
build tags:        cortexm baremetal linux arm rp2040 rp pico pico-w cyw43439 tinygo purego osusergo math_big_pure_go gc.conservative scheduler.cores serial.usb
garbage collector: conservative
scheduler:         cores
cached GOROOT:     /Users/haswalt/Library/Caches/tinygo/goroot-9337f541e113a04e1e9969a9c5b9f1da019c67ac44a7bc39208df2650d807963

But then checking tinygoenv -target=pico-w:

tinygo env -target=pico-w
GOOS="darwin"
GOARCH="amd64"
GOROOT="/usr/local/Cellar/go/1.24.4/libexec"
GOPATH="/Users/haswalt/go"
GOCACHE="/Users/haswalt/Library/Caches/tinygo"
CGO_ENABLED="1"
TINYGOROOT="/usr/local/Cellar/tinygo/0.38.0

Sometimes I did manage to get passed this error but it resulted in tinygo build using a different cached GOROOT which causes a different error about sync/atomic package not existing.

[haswalt]

Simple reproduction: https://github.com/haswalt/tinygo-poc

[davecheney]

Hi @haswalt

I think the problem is these variables aren't defined for the generic pico2 board. They are defined for boards like the badger-2040, as this board is a product that comes with the e-ink display hard wired. For your code, you'll have to replace each

main.go:20:22: undefined: machine.EPD_SCK_PIN
main.go:21:22: undefined: machine.EPD_SDO_PIN
main.go:24:45: undefined: machine.EPD_CS_PIN
main.go:24:65: undefined: machine.EPD_DC_PIN
main.go:24:85: undefined: machine.EPD_RESET_PIN
main.go:24:108: undefined: machine.EPD_BUSY_PIN

with the correct machine.GPIOxx defintion depending on how you've wired up your display.