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feat: Crowpanel V2 brightness control #203

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541623f
V2 brightness control
mverch67 Sep 13, 2025
b91421f
update comment
mverch67 Sep 13, 2025
e71fe45
added light() which is used by LGFXdriver
mverch67 Sep 13, 2025
f142bdf
update initialisation
mverch67 Sep 15, 2025
83681f4
add 0x18 command at the end acc. factory example
mverch67 Sep 15, 2025
6e994d7
Merge branch 'master' into crowpanelV2
mverch67 Sep 15, 2025
9603b1d
fix error
mverch67 Sep 16, 2025
42179ed
Merge branch 'master' into crowpanelV2
mverch67 Oct 5, 2025
c8be3cc
set brightness after initialization
mverch67 Oct 5, 2025
816ac86
brightness fix, increase default frequency
mverch67 Oct 5, 2025
33fae73
add Elecrow_V2_Light class
mverch67 Oct 7, 2025
baa08ee
Merge branch 'master' into crowpanelV2
mverch67 Oct 7, 2025
a4fb22f
send 0x10 to enable V2 display
mverch67 Oct 11, 2025
87a8216
Merge branch 'master' into crowpanelV2
mverch67 Nov 4, 2025
76d354f
update FREQ_WRITE to 15800000
mverch67 Nov 4, 2025
14dc991
Merge branch 'master' into crowpanelV2
mverch67 Dec 5, 2025
724fdbe
Merge branch 'master' into crowpanelV2
mverch67 Jan 13, 2026
48e3a59
Merge branch 'master' into crowpanelV2
mverch67 Feb 2, 2026
499f3a8
Merge branch 'master' into crowpanelV2
mverch67 Mar 3, 2026
dd894d9
Merge branch 'master' into crowpanelV2
mverch67 Apr 7, 2026
0ef43f7
Merge branch 'master' into crowpanelV2
mverch67 Jul 7, 2026
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131 changes: 110 additions & 21 deletions include/graphics/LGFX/LGFX_ELECROW70.h
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Original file line number Diff line number Diff line change
Expand Up @@ -6,15 +6,83 @@
#include <lgfx/v1/platforms/esp32s3/Bus_RGB.hpp>
#include <lgfx/v1/platforms/esp32s3/Panel_RGB.hpp>

#define ELECROW_V1_ADDR 0x18
#define ELECROW_V2_ADDR 0x30

#ifndef FREQ_WRITE
#define FREQ_WRITE 14000000
#define FREQ_WRITE 15800000
#endif

class Elecrow_V2_Light : public lgfx::v1::ILight
{
public:
struct config_t {
bool isV2 = false;
bool isV3 = false;
uint8_t brightness = 153; // 60%
};

const config_t &config(void) const { return _cfg; }
void config(const config_t &cfg) { _cfg = cfg; }

bool init(uint8_t brightness) override
{
Wire.beginTransmission(ELECROW_V2_ADDR);
if (Wire.endTransmission() == 0) {
sendI2CCommand(0x10);
_cfg.isV2 = true;
}
return true;
}
Comment on lines +28 to +36

@coderabbitai coderabbitai Bot Jul 7, 2026

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🎯 Functional Correctness | 🟠 Major | ⚡ Quick win

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
rg -nP 'isV3' --type=cpp --type-add 'header:*.h' --type=header
rg -nP '\.init\s*\(' -C2 include/graphics/LGFX/LGFX_ELECROW70.h

Repository: meshtastic/device-ui

Length of output: 158

🌐 Web query:

LovyanGFX ILight init setBrightness interface contract

💡 Result:

In the LovyanGFX library, ILight is an abstract base class (interface) defined in the lgfx::v1 namespace, responsible for abstracting backlight control [1][2]. The ILight interface contract consists of two primary pure virtual functions [1][2]: 1. bool init(uint8_t brightness) = 0; This method is responsible for initializing the backlight hardware, such as configuring PWM pins or I2C communication for a PMIC [2][3][4]. The brightness parameter typically defines the initial light intensity level (range 0–255) [1][5][2]. 2. void setBrightness(uint8_t brightness) = 0; This method updates the backlight intensity to the specified value in the range of 0–255 [1][5][2]. Concrete implementations, such as Light_PWM or those for I2C-controlled backlights, override these methods to provide platform-specific hardware control [1][3][4]. Within the broader architecture, a Panel_Device instance composes an ILight object [6][7]. When a user calls the high-level lcd.setBrightness(b) method on their LGFX device, the library internally delegates the call to the registered ILight implementation's setBrightness method [4][7]. The init process for the light component is triggered automatically when the main LGFX_Device::init function is called during the application startup [4][7].

Citations:

🏁 Script executed:

#!/bin/bash
set -euo pipefail

printf '\n== file outline ==\n'
ast-grep outline include/graphics/LGFX/LGFX_ELECROW70.h --view expanded || true

printf '\n== relevant file slice ==\n'
sed -n '1,220p' include/graphics/LGFX/LGFX_ELECROW70.h | cat -n

printf '\n== search for ELECROW variants and V3 ==\n'
rg -n "ELECROW|isV3|setBrightness\\(|init\\(uint8_t brightness\\)" include/graphics/LGFX -S

Repository: meshtastic/device-ui

Length of output: 10896

🏁 Script executed:

#!/bin/bash
set -euo pipefail

sed -n '220,250p' include/graphics/LGFX/LGFX_ELECROW70.h | cat -n

Repository: meshtastic/device-ui

Length of output: 752

🏁 Script executed:

#!/bin/bash
set -euo pipefail

sed -n '220,240p' include/graphics/LGFX/LGFX_ELECROW70.h | cat -n

Repository: meshtastic/device-ui

Length of output: 752

Detect V3 and apply the requested brightness in init(). _cfg.isV3 is never set anywhere, so the V3 path in setBrightness()/light()/sleep()/wakeup() is dead and V3 backlight control never activates. init(uint8_t brightness) also ignores the caller’s value and always sends 0x10, so startup brightness and getBrightness() are out of sync.

🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@include/graphics/LGFX/LGFX_ELECROW70.h` around lines 28 - 36, Update
ELECROW70::init(uint8_t brightness) so it detects the V3 device and sets
_cfg.isV3 when the V3 address/handshake is found, keeping the existing V2
detection intact. Also stop hardcoding the startup command: use the brightness
argument when sending the initial backlight command so init() matches
getBrightness() and the later setBrightness()/light()/sleep()/wakeup() paths
stay consistent.


// crowpanel V2 allows 5 brightness levels
// 0: off (0x05)
// 1 .. 51: (0x06)
// 52 .. 102: (0x07)
// 103 .. 153: (0x08)
// 154 .. 204: (0x09)
// 205 .. 255: (0x10)
// crowpanel V3 has level 0 (brightest) .. 245 (off)
void setBrightness(uint8_t brightness) override
{
if (_cfg.isV2) {
uint8_t cmd = (brightness + 50) / 51 + 5;
if (brightness >= 205)
cmd = 0x10;
sendI2CCommand(cmd);
_cfg.brightness = brightness;
} else if (_cfg.isV3) {
uint8_t brightnessV3 = 244 - (uint32_t(brightness) * 244 / 255);
sendI2CCommand(brightnessV3);
}
_cfg.brightness = brightness;
}

uint8_t getBrightness(void) const { return _cfg.brightness; }

virtual ~Elecrow_V2_Light(void) = default;

private:
// for V2/V3 microcontroller control
uint8_t sendI2CCommand(uint8_t cmd)
{
Wire.beginTransmission(ELECROW_V2_ADDR);
Wire.write(cmd);
uint8_t error = Wire.endTransmission();
if (error != 0)
ILOG_ERROR("failed to send command 0x%02x: %d", cmd, error);
return error;
}

config_t _cfg;
};

class LGFX_ELECROW70 : public lgfx::LGFX_Device
{
lgfx::Bus_RGB _bus_instance;
lgfx::Panel_RGB _panel_instance;
lgfx::Touch_GT911 _touch_instance;
Elecrow_V2_Light _light_instance;

public:
const uint16_t screenWidth = 800;
Expand All @@ -24,28 +92,37 @@ class LGFX_ELECROW70 : public lgfx::LGFX_Device

bool init_impl(bool use_reset, bool use_clear) override
{
ioex.attach(Wire);
ioex.setDeviceAddress(0x18);
ioex.config(1, TCA9534::Config::OUT);
ioex.config(2, TCA9534::Config::OUT);
ioex.config(3, TCA9534::Config::OUT);
ioex.config(4, TCA9534::Config::OUT);

ioex.output(1, TCA9534::Level::H);
ioex.output(3, TCA9534::Level::L);
ioex.output(4, TCA9534::Level::H);

pinMode(1, OUTPUT);
digitalWrite(1, LOW);
ioex.output(2, TCA9534::Level::L);
delay(20);
ioex.output(2, TCA9534::Level::H);
delay(100);
pinMode(1, INPUT);
Wire.beginTransmission(ELECROW_V1_ADDR);
if (Wire.endTransmission() == 0) {
ioex.attach(Wire);
ioex.setDeviceAddress(ELECROW_V1_ADDR);
ioex.config(1, TCA9534::Config::OUT);
ioex.config(2, TCA9534::Config::OUT);
ioex.config(3, TCA9534::Config::OUT);
ioex.config(4, TCA9534::Config::OUT);

ioex.output(1, TCA9534::Level::H);
ioex.output(3, TCA9534::Level::L);
ioex.output(4, TCA9534::Level::H);

pinMode(1, OUTPUT);
digitalWrite(1, LOW);
ioex.output(2, TCA9534::Level::L);
delay(20);
ioex.output(2, TCA9534::Level::H);
delay(100);
pinMode(1, INPUT);
}

return LGFX_Device::init_impl(use_reset, use_clear);
}

lgfx::ILight *light(void) const
{
// pointer is used by LGFXDriver to check for hasLight()
return _light_instance.config().isV2 || _light_instance.config().isV3 ? (lgfx::ILight *)&_light_instance : nullptr;
}

LGFX_ELECROW70(void)
{
{
Expand Down Expand Up @@ -132,18 +209,30 @@ class LGFX_ELECROW70 : public lgfx::LGFX_Device
_panel_instance.setTouch(&_touch_instance);
}

// Set the backlight control
{
auto cfg = _light_instance.config();
_light_instance.config(cfg);
_panel_instance.setLight(&_light_instance);
}

setPanel(&_panel_instance);
}

void sleep(void)
{
ioex.output(1, TCA9534::Level::L);
if (!_light_instance.config().isV2 && !_light_instance.config().isV3) {
ioex.output(1, TCA9534::Level::L);
}
_panel->setSleep(true);
}

void wakeup(void)
{
ioex.output(1, TCA9534::Level::H);
_panel->setSleep(false);
if (!_light_instance.config().isV2 && !_light_instance.config().isV3) {
ioex.output(1, TCA9534::Level::H);
}
}
Comment on lines 222 to 236

@coderabbitai coderabbitai Bot Jul 7, 2026

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🎯 Functional Correctness | 🟡 Minor | ⚡ Quick win

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
set -euo pipefail

# Show the relevant section with line numbers.
sed -n '180,280p' include/graphics/LGFX/LGFX_ELECROW70.h

# Find references to the light instance and sleep/wakeup behavior.
rg -n "_light_instance|setSleep\\(|isV2|isV3|brightness|0x05|backlight" include/graphics/LGFX -S

# List nearby files that may define panel/light behavior.
fd -a "LGFX_ELECROW70.h|LGFX_.*\\.h|*Light*" include/graphics

Repository: meshtastic/device-ui

Length of output: 17831

🏁 Script executed:

#!/bin/bash
set -euo pipefail

# Inspect the Elecrow light implementation in context.
sed -n '1,120p' include/graphics/LGFX/LGFX_ELECROW70.h

# Inspect the LGFX configuration wrapper for light/panel interactions.
sed -n '1,260p' include/graphics/LGFX/LGFXConfig.h

# Search for setSleep implementations and backlight behavior in the LGFX subtree.
rg -n "setSleep\\(|setLight\\(|ILight|setBrightness\\(|brightness\\s*=|sleep\\(" include/graphics/LGFX -S

Repository: meshtastic/device-ui

Length of output: 17233

🌐 Web query:

LovyanGFX Panel_Device setSleep attached light backlight sleep behavior ILight setBrightness 0

💡 Result:

In the LovyanGFX library, the setSleep(bool) function typically commands the display controller IC itself to enter a low-power mode (e.g., sending MIPI DCS commands like CMD_SLPIN) [1][2]. It does not inherently control the physical backlight GPIO pin [3][2]. Key points regarding your query: 1. Backlight Management: LovyanGFX does not automatically manage the physical backlight GPIO during sleep [3]. Because the library does not explicitly handle the backlight state during sleep transitions, you must manually control the backlight (e.g., set the GPIO pin to LOW) when preparing for system sleep [3]. 2. ILight and Brightness: The ILight interface provides the setBrightness(uint8_t brightness) method [4]. While setting brightness to 0 is intended to turn off or dim the backlight, its effectiveness depends entirely on the underlying hardware implementation of the light controller associated with your panel [5][6]. If the backlight hardware does not support dimming via the ILight interface, calling setBrightness(0) will have no effect [5]. 3. Recommendations: To ensure the backlight is off during sleep, you should explicitly set the backlight pin to an "off" state in your code before calling the system's sleep function [3]. Do not rely on Panel_Device::setSleep or ILight::setBrightness(0) to perform this hardware-specific power-down task [3][5]. For reference, the Panel_Device class acts as a base for hardware abstraction [7], but because backlight circuits vary significantly across different boards, the library leaves the physical GPIO management to the user to avoid unintended side effects or hardware damage [3].

Citations:

V2/V3 backlight still needs an explicit off/on command
_panel->setSleep(true) only puts the panel IC to sleep; it does not power down the backlight. For V2/V3, send brightness 0 in sleep() and restore the saved brightness in wakeup(), otherwise the backlight can stay lit while the panel is asleep.

🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@include/graphics/LGFX/LGFX_ELECROW70.h` around lines 222 - 236, The
sleep/wakeup handling in LGFX_ELECROW70 currently only toggles panel sleep and
the IO expander for non-V2/V3 boards, so V2/V3 backlight remains on. Update the
sleep() and wakeup() methods to explicitly turn the backlight off by sending
brightness 0 during sleep and restore the previously saved brightness during
wakeup, while keeping the existing _panel->setSleep(true/false) and TCA9534
output logic intact. Use the existing config checks on _light_instance and the
current backlight control path in LGFX_ELECROW70 to place the fix.


private:
Expand Down
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