diff --git a/board/boards/cuatro.h b/board/boards/cuatro.h
index 4625a8a5a2a..8e47c95f023 100644
--- a/board/boards/cuatro.h
+++ b/board/boards/cuatro.h
@@ -97,6 +97,14 @@ void cuatro_init(void) {
   // Sound codec
   sound_init();
   set_gpio_output(GPIOA, 5, true);
+  set_gpio_alternate(GPIOA, 2, GPIO_AF8_SAI4);    // SAI4_SCK_B
+  set_gpio_alternate(GPIOC, 0, GPIO_AF8_SAI4);    // SAI4_FS_B
+  set_gpio_alternate(GPIOD, 11, GPIO_AF10_SAI4);  // SAI4_SD_A
+  set_gpio_alternate(GPIOE, 3, GPIO_AF8_SAI4);    // SAI4_SD_B
+  set_gpio_alternate(GPIOE, 4, GPIO_AF10_SAI4);   // SAI4_D2
+  set_gpio_alternate(GPIOE, 5, GPIO_AF10_SAI4);   // SAI4_CK2
+  set_gpio_alternate(GPIOE, 6, GPIO_AF10_SAI4);   // SAI4_MCLK_B
+
 }
 
 const board board_cuatro = {
diff --git a/board/drivers/sound.h b/board/drivers/sound.h
index f87fbba130a..452a0d3c975 100644
--- a/board/drivers/sound.h
+++ b/board/drivers/sound.h
@@ -1,6 +1,22 @@
 
 const uint8_t sine[360] = { 127U, 129U, 131U, 133U, 135U, 138U, 140U, 142U, 144U, 146U, 149U, 151U, 153U, 155U, 157U, 159U, 161U, 164U, 166U, 168U, 170U, 172U, 174U, 176U, 178U, 180U, 182U, 184U, 186U, 188U, 190U, 192U, 194U, 196U, 197U, 199U, 201U, 203U, 205U, 206U, 208U, 210U, 211U, 213U, 215U, 216U, 218U, 219U, 221U, 222U, 224U, 225U, 227U, 228U, 229U, 230U, 232U, 233U, 234U, 235U, 236U, 238U, 239U, 240U, 241U, 242U, 242U, 243U, 244U, 245U, 246U, 247U, 247U, 248U, 249U, 249U, 250U, 250U, 251U, 251U, 252U, 252U, 252U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 253U, 252U, 252U, 252U, 251U, 251U, 250U, 250U, 249U, 249U, 248U, 247U, 247U, 246U, 245U, 244U, 243U, 243U, 242U, 241U, 240U, 239U, 238U, 237U, 235U, 234U, 233U, 232U, 231U, 229U, 228U, 227U, 225U, 224U, 222U, 221U, 219U, 218U, 216U, 215U, 213U, 212U, 210U, 208U, 207U, 205U, 203U, 201U, 199U, 198U, 196U, 194U, 192U, 190U, 188U, 186U, 184U, 182U, 180U, 178U, 176U, 174U, 172U, 170U, 168U, 166U, 164U, 162U, 160U, 157U, 155U, 153U, 151U, 149U, 147U, 144U, 142U, 140U, 138U, 136U, 133U, 131U, 129U, 127U, 124U, 122U, 120U, 118U, 116U, 113U, 111U, 109U, 107U, 105U, 102U, 100U, 98U, 96U, 94U, 92U, 90U, 87U, 85U, 83U, 81U, 79U, 77U, 75U, 73U, 71U, 69U, 67U, 65U, 63U, 61U, 59U, 58U, 56U, 54U, 52U, 50U, 49U, 47U, 45U, 43U, 42U, 40U, 38U, 37U, 35U, 34U, 32U, 31U, 29U, 28U, 27U, 25U, 24U, 23U, 21U, 20U, 19U, 18U, 17U, 16U, 14U, 13U, 12U, 12U, 11U, 10U, 9U, 8U, 7U, 7U, 6U, 5U, 4U, 4U, 3U, 3U, 2U, 2U, 1U, 1U, 1U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 0U, 1U, 1U, 1U, 2U, 2U, 3U, 3U, 4U, 4U, 5U, 6U, 6U, 7U, 8U, 9U, 9U, 10U, 11U, 12U, 13U, 14U, 15U, 16U, 17U, 19U, 20U, 21U, 22U, 24U, 25U, 26U, 28U, 29U, 30U, 32U, 33U, 35U, 36U, 38U, 40U, 41U, 43U, 45U, 46U, 48U, 50U, 52U, 53U, 55U, 57U, 59U, 61U, 63U, 65U, 67U, 69U, 70U, 72U, 74U, 77U, 79U, 81U, 83U, 85U, 87U, 89U, 91U, 93U, 95U, 98U, 100U, 102U, 104U, 106U, 108U, 111U, 113U, 115U, 117U, 119U, 122U, 124U };
 
+void sai4_init(void) {
+  register_set(&SAI4->GCR, 0U, SAI_GCR_SYNCIN_Msk | SAI_GCR_SYNCOUT_Msk);
+
+  // mono audio in
+  register_set(&SAI4_Block_A->CR1, SAI_xCR1_MONO | SAI_xCR1_DMAEN | (0b01 << SAI_xCR1_SYNCEN_Pos) | (0b100 << SAI_xCR1_DS_Pos) | (0b11 << SAI_xCR1_MODE_Pos), 0x0FFB3FEFU);
+  register_set(&SAI4_Block_A->CR2, 0U, 0xFFFFU); // TODO: mute detection
+  register_set(&SAI4_Block_A->FRCR, (15U << SAI_xFRCR_FRL_Pos), 0x7FFFFU); // is this correct?
+  register_set(&SAI4_Block_A->SLOTR, (0b11 << SAI_xSLOTR_SLOTEN_Pos) | (1U << SAI_xSLOTR_NBSLOT_Pos) | (0b01 << SAI_xSLOTR_SLOTSZ_Pos), 0xFFFF0FDFU); // NBSLOT definition is vague
+
+  // mono mic out
+  // register_set(&SAI4_Block_B->CR1, SAI_xCR1_MONO | SAI_xCR1_DMAEN | (0b01 << SAI_xCR1_SYNCEN_Pos) | (0b100 << SAI_xCR1_DS_Pos) | (0b10 << SAI_xCR1_MODE_Pos), 0x0FFB3FEFU);
+
+  register_set_bits(&SAI4_Block_A->CR1, SAI_xCR1_SAIEN);
+
+}
+
 void sound_init(void) {
   // Init DAC
   register_set(&DAC1->MCR, 0U, 0xFFFFFFFFU);
@@ -26,4 +42,6 @@ void sound_init(void) {
   register_set(&TIM7->CR1, TIM_CR1_ARPE | TIM_CR1_URS, 0x088EU);
   TIM7->SR = 0U;
   TIM7->CR1 |= TIM_CR1_CEN;
+
+  sai4_init();
 }
\ No newline at end of file
diff --git a/board/main.c b/board/main.c
index 061a913814b..d87be9ced02 100644
--- a/board/main.c
+++ b/board/main.c
@@ -156,6 +156,10 @@ void tick_handler(void) {
     harness_tick();
     simple_watchdog_kick();
 
+#ifdef STM32H7
+    print("SAI4 A DR: 0x"); puth(SAI4_Block_A->DR); print("\n");
+#endif
+
     // decimated to 1Hz
     if (loop_counter == 0U) {
       can_live = pending_can_live;
diff --git a/board/stm32h7/peripherals.h b/board/stm32h7/peripherals.h
index b60f19016d7..156dda31683 100644
--- a/board/stm32h7/peripherals.h
+++ b/board/stm32h7/peripherals.h
@@ -118,6 +118,9 @@ void peripherals_init(void) {
   RCC->AHB1ENR |= RCC_AHB1ENR_ADC12EN; // Enable ADC12 clocks
   RCC->APB1LENR |= RCC_APB1LENR_DAC12EN; // DAC
 
+  // Audio
+  RCC->APB4ENR |= RCC_APB4ENR_SAI4EN;  // SAI4
+
   // Timers
   RCC->APB2ENR |= RCC_APB2ENR_TIM1EN;  // clock source timer
   RCC->APB1LENR |= RCC_APB1LENR_TIM2EN;  // main counter