IWR6843ISK: Critical Data Port TLV Misalignment/Corruption Issue with Specific TLV Types (2, 3, 4, 5, 8) - Node.js Implementation

Tool/software:

I am writing back as I have failed to resolve a critical data parsing issue despite trying standard alignment fixes. My setup uses Node.js for parsing data streamed from the Data Port based on the following configuration.

Please note: My application uses a custom Node.js parser and does not rely on any Python-based tools or GUIs from TI.

Summary of Persistent Problems:

1. TLV Chain Corruption (TLV 2 & 3):

   • TLVs 1, 6, 7, and 9 are received correctly.

   • When TLV 2 (Range Profile) and/or TLV 3 (Noise Profile) are included (e.g., guiMonitor -1 1 1 1 0 0 1), the next TLV header (Type and Length) is always corrupted, resulting in nonsensical values (e.g., $143525728$).

   • I have attempted the two most common solutions:

     • Applying 4-byte and 8-byte boundary alignment after consuming the tlv.length in the main loop (processBuffer).

     • Testing 4-byte stepping inside the parseRangeProfile and parseNoiseProfile functions (assuming 2-byte data + 2-byte padding per point).

   • All alignment solutions failed, leading me to believe the issue is deeply rooted in the protocol's definition under this specific configuration.

2. TLV 4, 5, and 8 Transmission Failure:

   • When attempting to request TLV 4 (Azimuth Static Heatmap), 5 (Range-Doppler Heatmap), or 8 (Azimuth/Elevation Static Heatmap) by setting the corresponding guiMonitor arguments to $1$, the sensor completely stops transmitting any data (including the other working TLVs).

Critical Questions:

1. TLV 2 and 3 Data Format/Alignment:

   • Given the persistent misalignment, can you confirm the exact alignment rule for the end of the Range Profile (TLV 2) and Noise Profile (TLV 3) data blocks?

   • Is the internal structure of these TLVs strictly contiguous 2-byte data points or are the points individually padded to a 4-byte or 8-byte boundary?

2. TLV 4, 5, and 8 Configuration Requirements:

   • Why does requesting TLV 4, 5, or 8 lead to a complete halt in data transmission?

   • Is a specific configuration command (e.g., related to adcbufCfg, BPM, or a different channelCfg) missing or incorrect in my startCommands list, which is required to enable the computation of these heatmap TLVs?

3. When parsing the TLV header, the type and length are obtained. Does the length include the TLV header itself?

I referred to the datasheet at https://dev.ti.com/tirex/explore/node?node=A__AaagUFIod1NcG0sE-noAfw__radar_toolbox__1AslXXD__LATEST and believe I mapped it correctly, but just in case, I’m including my implementation here.

startCommands = [
'sensorStop',
'flushCfg',
'dfeDataOutputMode 1',
'channelCfg 15 5 0',
'adcCfg 2 1',
'adcbufCfg -1 0 1 1 1',
'profileCfg 0 60 567 7 57.14 0 0 70 1 256 5209 0 0 158',
'chirpCfg 0 0 0 0 0 0 0 1',
'chirpCfg 1 1 0 0 0 0 0 4',
'frameCfg 0 1 16 0 100 1 0',
'lowPower 0 0',
'guiMonitor -1 1 1 1 0 0 1',
'cfarCfg -1 0 2 8 4 3 0 15 1',
'cfarCfg -1 1 0 4 2 3 1 15 1',
'multiObjBeamForming -1 1 0.5',
'clutterRemoval -1 0',
'calibDcRangeSig -1 0 -5 8 256',
'extendedMaxVelocity -1 0',
'bpmCfg -1 0 0 1',
'lvdsStreamCfg -1 0 0 0',
'compRangeBiasAndRxChanPhase 0.0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0',
'measureRangeBiasAndRxChanPhase 0 1.5 0.2',
'CQRxSatMonitor 0 3 5 121 0',
'CQSigImgMonitor 0 127 4',
'analogMonitor 0 0',
'aoaFovCfg -1 -90 90 -90 90',
'cfarFovCfg -1 0 0 8.92',
'cfarFovCfg -1 1 -1 1.00',
'calibData 0 0 0',
'sensorStart'
]

// TLV type 2 - Range Profile.
function parseRangeProfile(buffer, offset, length) {
if (length % 2 !== 0) {
console.warn('TLV type 2, Range Profile length is not multiple of 2, skipping parsing')
return []
}

const numPoints = length / 2
const profile = new Array(numPoints)

for (let i = 0; i < numPoints; i++) {
const base = offset + i * 2
const raw = buffer.readUInt16LE(base)
profile[i] = raw / 512.0
}

return profile
}

// TLV type 3 - Noise Profile.
function parseNoiseProfile(buffer, offset, length) {
if (length % 2 !== 0) {
console.warn('TLV type 3, Noise Profile length is not multiple of 2, skipping parsing')
return []
}

const numPoints = length / 2
const profile = new Array(numPoints)

for (let i = 0; i < numPoints; i++) {
const base = offset + i * 2
const raw = buffer.readUInt16LE(base)
profile[i] = raw / 512.0
}

return profile
}

// TLV type 4 - Azimuth Static Heatmap.
function parseAzimuthStaticHeatmap(buffer, offset, length) {
const numRangeBins = 256
const numVirtualAntAzim = 8

if (length !== numRangeBins * numVirtualAntAzim * 4) {
console.warn('TLV type 4, Azimuth Static Heatmap length mismatch, skipping parsing')
return []
}

const heatmap = []

for (let r = 0; r < numRangeBins; r++) {
const row = []
for (let a = 0; a < numVirtualAntAzim; a++) {
const base = offset + 4 * (r * numVirtualAntAzim + a)
const imag = buffer.readInt16LE(base)
const real = buffer.readInt16LE(base + 2)
row.push({ real, imag })
}
heatmap.push(row)
}

return heatmap
}

// TLV type 5 - Range-Doppler Heatmap.
function parseRangeDopplerHeatmap(buffer, offset, length) {
const numRangeBins = 256
const numDopplerBins = 16

if (length !== numRangeBins * numDopplerBins * 2) {
console.warn('TLV type 5, Range-Doppler Heatmap length mismatch, skipping parsing')
return []
}

const heatmap = []

for (let r = 0; r < numRangeBins; r++) {
const row = []
for (let d = 0; d < numDopplerBins; d++) {
const base = offset + 2 * (r * numDopplerBins + d)
const raw = buffer.readUInt16LE(base)
row.push(raw / 512.0)
}
heatmap.push(row)
}

return heatmap
}

// TLV type 8 - Azimuth/Elevation Static Heatmap.
function parseAzimuthElevationStaticHeatmap(buffer, offset, length) {
const numRangeBins = 256
const numVirtualAntennas = 12

if (length !== numRangeBins * numVirtualAntennas * 4) {
console.warn('TLV type 8, Azimuth/Elevation Static Heatmap length mismatch, skipping parsing')
return []
}

const heatmap = []

for (let r = 0; r < numRangeBins; r++) {
const row = []
for (let a = 0; a < numVirtualAntennas; a++) {
const base = offset + 4 * (r * numVirtualAntennas + a)
const imag = buffer.readInt16LE(base)
const real = buffer.readInt16LE(base + 2)
row.push({ real, imag })
}
heatmap.push(row)
}

return heatmap
}

Thank you for providing a technical answer to these protocol-level questions.