I haven't seen what current your load draws, so have no idea of shunt resistance or power dissipation. The uC you're using has an on-board 1.2V reference that may be used with the ADC module; I suggest you could use it and feed the shunt voltage into the ADC.
I recommend you translate the shunt voltage to reside within the 0-1.2V range, for the ADC (allows monitoring of both positive & negative shunt voltages). The example circuit does this for the Vshunt range of around -1V to +1V, with the centrepoint around 0.65V. Play around with the resistor values to get the range you require.
Unfortunately, the above setup also attenuates (reduces amplitude of) the signal. If this is a problem, the shunt voltage may be offset using a foward biased diode.
I recommend you translate the shunt voltage to reside within the 0-1.2V range, for the ADC (allows monitoring of both positive & negative shunt voltages). The example circuit does this for the Vshunt range of around -1V to +1V, with the centrepoint around 0.65V. Play around with the resistor values to get the range you require.
Unfortunately, the above setup also attenuates (reduces amplitude of) the signal. If this is a problem, the shunt voltage may be offset using a foward biased diode.