CC2640ADC采样问题

请教一个问题，CC2640的ADC内部参考电压可以设置到4.3V，那我对聚合物锂电池进行电压采样是否可以直接把聚合物锂电池接到采样IO口上（或者加一个限流保护电阻）；

如果不行，那采用电阻分压的办法，那么电压采样IO口对地的等效电阻是多大？

不行。 你是要测芯片当前的电压吗？可以参考BLE-STACK里的battservice.c. 用的是内部的battery monitor.

static uint8_t battMeasure(void)
{
  uint32_t percent;

  // Call measurement setup callback
  if (battServiceSetupCB != NULL)
  {
    battServiceSetupCB();
  }

  // Read the battery voltage (V), only the first 12 bits
  percent = AONBatMonBatteryVoltageGet();

  // Convert to from V to mV to avoid fractions.
  // Fractional part is in the lower 8 bits thus converting is done as follows:
  // (1/256)/(1/1000) = 1000/256 = 125/32
  // This is done most effectively by multiplying by 125 and then shifting
  // 5 bits to the right.
  percent = (percent * 125) >> 5;
  // Convert to percentage of maximum voltage.
  percent = ((percent* 100) / battMaxLevel);
 
  // Call measurement teardown callback
  if (battServiceTeardownCB != NULL)
  {
    battServiceTeardownCB();
  }
   
  return percent;
}

是这样的，我设备是聚合物锂电池（标称3.7V，最大4.2V）供电，经过DCDC给CC2540供电，软件上没什么问题，主要是硬件上。

你的意思是需要直接测电池的电压？而不是供电电压？

e2e对应解答供参考：

https://e2e.ti.com/support/wireless_connectivity/bluetooth_low_energy/f/538/t/430107

The ADC input resistance is now listed in the datasheet (p 17 table 5.12 in the CC2640). You can also look at https://e2e.ti.com/support/wireless_connectivity/bluetooth_low_energy/f/538/t/452067