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Fix SSD1306 128x32: wrong column-start address #707

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Fix SSD1306 128x32: wrong column-start address #707

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665eb2b
Fix SSD1306 128x32: wrong column-start address (0x12 -> 0x10)
jonwaterschoot Aug 4, 2026
03c2061
Batch SSD1306 I2C page writes into one transaction
jonwaterschoot Aug 4, 2026
3d4803e
Make the SSD1306 column-start address configurable
jonwaterschoot Aug 8, 2026
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61 changes: 36 additions & 25 deletions src/dev/oled_ssd130x.h
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,19 @@ class SSD130xI2CTransport

void SendData(uint8_t* buff, size_t size)
{
// SSD1306 auto-increments its column pointer after one 0x40
// prefix, so a page can go out in a single transaction.
constexpr size_t kMaxBurst = 132; // widest driver width used here (128) + margin
if(size <= kMaxBurst - 1)
{
uint8_t buf[kMaxBurst];
buf[0] = 0X40;
for(size_t i = 0; i < size; i++)
buf[1 + i] = buff[i];
i2c_.TransmitBlocking(
i2c_address_, buf, static_cast<uint16_t>(size + 1), 1000);
return;
}
for(size_t i = 0; i < size; i++)
{
uint8_t buf[2] = {0X40, buff[i]};
Expand Down Expand Up @@ -257,11 +270,21 @@ class SSD130xDriver
struct Config
{
typename Transport::Config transport_config;

/** Higher column start address sent before each page write.
* 64x32 panels are wired to the middle 64 columns of the
* controller's 128-column RAM and so need a 32-column offset
* (0x10 | 32 >> 4 == 0x12); every other geometry starts at
* column 0 (0x10). Override for panels that map differently:
* the offset is (controller RAM columns - panel width) / 2,
* where the SSD1306/SSD1309 have 128 columns and the SH1106 132. */
uint8_t high_column_addr = (width == 64 && height == 32) ? 0x12 : 0x10;
};

void Init(Config config)
{
transport_.Init(config.transport_config);
high_column_addr_ = config.high_column_addr;

// Init routine...

Expand Down Expand Up @@ -382,18 +405,11 @@ class SSD130xDriver
void Update()
{
uint8_t i;
uint8_t high_column_addr;
switch(height)
{
case 32: high_column_addr = 0x12; break;

default: high_column_addr = 0x10; break;
}
for(i = 0; i < (height / 8); i++)
{
transport_.SendCommand(0xB0 + i);
transport_.SendCommand(0x00);
transport_.SendCommand(high_column_addr);
transport_.SendCommand(high_column_addr_);
transport_.SendData(&buffer_[width * i], width);
}
};
Expand All @@ -406,6 +422,7 @@ class SSD130xDriver
protected:
Transport transport_;
uint8_t buffer_[width * height / 8];
uint8_t high_column_addr_;
};

/**
Expand Down Expand Up @@ -482,13 +499,20 @@ class SSD1307Driver
struct Config
{
typename Transport::Config transport_config;

/** Higher column start address sent before each page write.
* See SSD130xDriver::Config::high_column_addr — no SSD1307 alias
* is 64x32 today, but the member is kept in step so both drivers
* are configured the same way. */
uint8_t high_column_addr = (width == 64 && height == 32) ? 0x12 : 0x10;
};

void Init(Config config)
{
transport_.Init(config.transport_config);

useDma_ = config.transport_config.useDma;
high_column_addr_ = config.high_column_addr;
useDma_ = config.transport_config.useDma;

// Init routine...
uint8_t uDispayOffset;
Expand Down Expand Up @@ -594,18 +618,11 @@ class SSD1307Driver
else
{
uint8_t i;
uint8_t high_column_addr;
switch(height)
{
case 32: high_column_addr = 0x12; break;

default: high_column_addr = 0x10; break;
}
for(i = 0; i < (height / 8); i++)
{
transport_.SendCommand(0xB0 + i);
transport_.SendCommand(0x00);
transport_.SendCommand(high_column_addr);
transport_.SendCommand(high_column_addr_);
transport_.SendData(&buffer_[width * i], width);
}
updateing_ = false;
Expand All @@ -624,21 +641,15 @@ class SSD1307Driver
uint8_t transferPagesCount_;
uint8_t transferingPage_;
bool useDma_;
uint8_t high_column_addr_;

void TransferPageDma(uint8_t page)
{
transferingPage_ = page;

uint8_t high_column_addr;
switch(height)
{
case 32: high_column_addr = 0x12; break;

default: high_column_addr = 0x10; break;
}
uint8_t commands[] = {static_cast<uint8_t>(0xB0 + transferingPage_),
0x00,
high_column_addr};
high_column_addr_};
transport_.SendCommands(commands, 3);
// transport_.SendCommand(0xB0 + transferingPage_);
// transport_.SendCommand(0x00);
Expand Down