FarmOne board: request for quote

From: IEMI Labs, [email protected] · Date: 4 November 2026 · Reference: IEMI-FO-VB-A

We are asking for a turnkey quote: finish the design of our valve-cover board, make it, assemble it, test it, and deliver boards that are ready to run. When a board arrives, we power it from its battery, put in our microSD card, and it starts our software. We do no setup, soldering or configuration.

All files are in the design pack (zip). The board, part by part: iemilabs.com/build/farmone-boards.

1. The board

One rigid-flex board in the valve cover of a 600 L stock trough: an 8-layer 248 × 256 mm main wing (RV1126B with a heat block to the cover floor, 1 GB LPDDR4X, 8 GB eMMC, MEMS clocks, latched microSD, ATECC608B security and ID chips, ESP32-S3-WROOM-1 always-on module, Quectel BG95-M3 LTE-M/GNSS modem with a soldered MFF2 eSIM, LTE chip antenna, GNSS patch, VL53L1X float-height chip, Omron D2F-01 tamper switch, camera supplies); a 30 mm two-layer flex bridge; a 4-layer 228 × 256 mm power wing (MPPT solar charger, 3.3 V supply, fuel gauge, four Keystone 1042 18650 holders with a thermistor, piezo sounder, solder pads for the panel, the water meter and the water probe); four small rigid tabs on flex arms (two Sony IMX415 camera chips under M12 lens holders, two Melexis MLX90640 heat-camera chips); two 52 × 10 lamp strips with 8 WS2812B LEDs each; and a 138 × 16 end strip (IM69D130 mic with a gasket, SHT45 air chip).

The outline, sections and placement of all 71 parts are fixed (KiCad 10 file, design rule check: 0 violations), each checked against our mechanical CAD. Please keep the outline and part positions, and tell us if anything must move.

2. Parts

Ref	Part	Where
U1	Rockchip RV1126B, FCCSP-409, 0.65 mm pitch, side A down under a heat block to the cover floor	main
HS1	Aluminium block 20 × 20 with 1 mm gap pads, from the RV1126B down to the cover floor over the shaded float bay	main
J1	microSD socket with a hinged, latched lid (Amphenol 101-00660 class), fitted on every board: our software starts from the card; reached by lifting the valve cover off	main
U90	microSD card power switch (TPS22917-class load switch, 3.3 V, driven by the card power-enable pin) with a 10 kΩ discharge resistor: a stuck card can be power-cycled	main
U91	microSD ESD and filter array, 6 lines (TPD6F003-class), with 22 Ω series resistors on CLK, CMD and D0–D3 and the card-detect line	main
U12	ST VL53L1X time-of-flight chip (27° cone) over the Ø10 floor window, looking down at the float	main
SW1	Omron D2F-01, plunger down through the Ø4 floor hole onto a 5 mm pin on the bay partition: pressed while the cover sits on the trough	main
TP1	Factory pads: USB 2.0, debug serial, boot, rails, current sense	main
C1	RV1126B decoupling field (over the chip, side B)	main
U2	LPDDR4X 8 Gbit ×32 (1 GB), 200-ball FBGA	main
U11	eMMC 5.1 8 GB industrial, 153-ball FBGA; shipped empty (the processor tries the eMMC before the card, so an image here would win): our loader on the card is set to read the card first (shipped empty, so the card always starts first; our loader on the card reads the card first)	main
U3	Power: rails for the RV1126B (core, NPU, logic, DDR, 1.8/3.3 V) from the cell rail, switched off while it sleeps	main
Y1	24 MHz MEMS oscillator (SiTime SiT8008 class)	main
Y2	32.768 kHz MEMS oscillator (SiTime SiT1533 class)	main
U8	Microchip ATECC608B security chip, UDFN-8: signs every call and the daily summary	main
U9	ID EEPROM 2 kbit (product, board version, serial, calibration)	main
U40	Espressif ESP32-S3-WROOM-1-N8R8 (certified): always awake on 0.1 W, reads the meter, float, heat chips and mic, wakes the RV1126B when stock come; BLE to the farmer’s phone at the trough	main
U41	Quectel BG95-M3 LTE-M / NB-IoT modem with GNSS, LCC (calls and clips to the farmer off-site)	main
U42	MFF2 eSIM, soldered (no SIM socket)	main
ANT3	25 × 25 ceramic GNSS patch facing up through the HDPE top, beside the solar panel (trough location and theft tracking)	main
U43	GNSS low-noise amplifier and SAW filter for the patch	main
U36	Level shifter for the call-light data lines (3.3 to 5 V)	main
U21	Camera LDOs 2.9 / 1.8 / 1.1 V for the paddock A camera chip	main
U22	Camera LDOs 2.9 / 1.8 / 1.1 V for the paddock B camera chip (over the bridge)	main
U14	VL53L1X 2.8 V LDO and I²C pull-ups	main
U25	I²C and PDM buffers for the end strip	main
U50	TI BQ25798 class buck-boost charger with MPPT from the 6 W panel, up to 1 A into the cells, NTC input, 0–45 °C charge window	power
L50	1 µH shielded inductor for the charger	power
U51	3.3 V buck for the always-on rail and the eFuse to the RV1126B rails over the bridge	power
U53	TI BQ2970 1-cell Li-ion protector + dual N-FET on the four-cell pack (short, over-current, over-discharge cut-off at 2.8 V)	power
U52	MAX17260 class cell fuel gauge: the app shows days of cloud left	power
BZ1	Piezo sounder Ø12 under the tone holes in the cover top (call tone)	power
U31	Sounder driver	power
PD1	Solder pads for the 6 W panel lead, strain-relief slot beside them	power
PD2	Solder pads for the water meter’s reed pulse wires	power
PD3	Solder pads for the DS18B20 water probe’s three wires (the probe stays in the water through its gland)	power
TP2	Factory pads: cell rail, charger status, panel in	power
U20A	Sony IMX415-AAQR-C 8 MP colour camera chip (C1, 1/2.8 in), looking 30° out over paddock A and 15° down	camA
LH1A	M12 low-profile lens holder with a 102° × 67° lens; lens front just inside the water-side face	camA
Y20A	Camera 37.125 MHz MEMS oscillator	camA
U24A	Melexis MLX90640ESF-BAA heat-camera chip, 110° × 75°, TO-39 can (leads through the tab)	heatA
U26A	MLX90640 3.3 V LDO and I²C pull-ups	heatA
U20B	Sony IMX415-AAQR-C 8 MP colour camera chip (C1, 1/2.8 in), looking 30° out over paddock B and 15° down	camB
LH1B	M12 low-profile lens holder with a 102° × 67° lens; lens front just inside the water-side face	camB
Y20B	Camera 37.125 MHz MEMS oscillator	camB
U24B	Melexis MLX90640ESF-BAA heat-camera chip, 110° × 75°, TO-39 can (leads through the tab)	heatB
U26B	MLX90640 3.3 V LDO and I²C pull-ups	heatB
MK1	Infineon IM69D130 MEMS mic, port to the end face through a 2 mm gasket (calving, distress calls, the pump)	end
GK1	Silicone sound gasket Ø5 × 2 from the mic to the end-face port	end
U27	Sensirion SHT45 temperature and humidity chip behind the end vents (frost and heat stress), slot cut round it in the strip	end
DA1	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampA
DA2	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampA
DA3	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampA
DA4	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampA
DA5	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampA
DA6	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampA
DA7	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampA
DA8	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampA
DB1	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampB
DB2	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampB
DB3	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampB
DB4	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampB
DB5	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampB
DB6	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampB
DB7	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampB
DB8	RGB LED with driver, 5050 (WS2812B class), under the call-light slot: green water OK, amber look, red call	lampB
BT1	Keystone 1042 SMT holder for one 18650 cell (Samsung INR18650-35E)	power
BT2	Keystone 1042 SMT holder for one 18650 cell (Samsung INR18650-35E)	power
BT3	Keystone 1042 SMT holder for one 18650 cell (Samsung INR18650-35E)	power
BT4	Keystone 1042 SMT holder for one 18650 cell (Samsung INR18650-35E)	power
RT1	NTC thermistor 10 k, 0603, between the first two cell holders, read by the charger so charging holds outside 0–45 °C	power

Each part’s size, side and position is in farmone-board-parts.csv in the pack. Ask before you substitute a part.

3. Scope of work

1. Schematic from Rockchip’s RV1126B reference design and Espressif’s ESP32-S3 hardware design guide and our block list. We review it before layout.
2. Layout in our outline and placement: the RV1126B memory and power routing, impedance-controlled MIPI and USB, and RF for every antenna keep-out. Lay the fast lines on a solid ground plane (inner layer 1, supply on inner layer 2; on a 2-layer section the whole bottom is ground under the module), with one via beside each ground and supply pad and no vias in pads unless you quote filled and capped vias (IPC-4761 type VII); no copper or vias in the antenna keep-out on any layer, none under the card socket; route the impedance lines first (camera MIPI pairs 100 Ω differential, USB 90 Ω, antenna 50 Ω) and add an impedance test coupon. Include the stack-up proposal and DFM, and a rigid-flex drawing (bend lines, stiffeners, coverlay).
3. Fabrication of the rigid-flex board.
4. Sourcing of all parts.
5. Assembly, both sides, with X-ray inspection of the ball-grid parts. Conformal coating (IPC-CC-830), with the sensors, sockets, connectors and antennas masked.
6. Board support package: U-Boot and a Linux device tree for this layout from Rockchip’s RV1126B SDK. A Rockchip SDK image must start from the microSD card. Camera drivers: paddock camera (one each side) IMX415 at 3840 × 2160, 5 fps; paddock camera (one each side) IMX415 at 3840 × 2160, 5 fps. Flash our ESP32-S3 image (we send it). We add our own software on top.
7. Test of every board to the acceptance list in §5, with a test report per serial number.
8. Deliverables: KiCad (or Altium) source, Gerbers, drill, pick-and-place, BOM, stack-up, test procedure and reports, and the BSP source.

4. “Ready to run” on delivery

This is the most important part of the job:

• Every board arrives assembled, programmed and tested.
• We put our microSD card in (J1, a hinged, latched socket) and power it, and it starts. No soldering, no jumpers, no settings, no flashing.
• The ID EEPROM is written with the serial number and board revision.
• The security chip is provisioned per the steps we will send.

Please quote both battery options:

• A: cells fitted. 4 × Samsung INR18650-35E soldered to the pack pads, protection checked, charged to storage level, and shipped as cells in equipment (UN3481). Please tell us your rules for this.
• B: cells not fitted. A short, polarised battery lead and plug on the pack pads, plus one charged pack per board. Nothing else to do on our side.

5. Acceptance tests (each board, with report)

1. Current-limited first power-on: no short, idle current within the agreed limit.
2. Rails: every power rail within ±3 %.
3. Boot: starts the Rockchip SDK image from the microSD card to a shell over the debug UART; the eMMC is detected and can be written.
4. Paddock camera (one each side): IMX415 streams 3840 × 2160 at 5 fps with no lost frames over 10 minutes, and a frame of a test chart is saved.
5. Paddock camera (one each side): IMX415 streams 3840 × 2160 at 5 fps with no lost frames over 10 minutes, and a frame of a test chart is saved.
6. Heat camera (one each side): reads a full 32 × 24 frame of a warm target.
7. Heat camera, close: reads a full 32 × 24 frame of a warm target.
8. Radios: U40 (Espressif ESP32-S3-WROOM-1-N8R8); U41 (Quectel BG95-M3 LTE-M / NB-IoT modem with GNSS): each joins or answers a test station.
9. Sensors and outputs, each read or driven in turn: U91 (microSD ESD and filter array), BZ1 (Piezo sounder Ø12 under the tone holes in the cover top), U31 (Sounder driver), U27 (Sensirion SHT45 temperature and humidity chip behind the end vents).
10. Battery: charges from the charge input at the set voltage; protection cuts off at low voltage and on a short; the gauge reads charge; the thermistor reads.
11. Power: the draw in each state of our day (watching about 0.25 W, stock at the water about 1.6 W), so we can check our design review: at least 48 hours, cells aged and cold.
12. Heat: the RV1126B temperature after 1 hour at full load in a 35 °C room, against our estimate.

6. Quantities and timing

Item	Quantity
Rev A boards	5 and 20: please quote both
Budget prices	for 100 and 1,000 boards
Quote wanted	within two weeks of this request
Boards wanted	please give your lead times for design, fabrication and assembly

7. Our design review

Before we order, every board-level number is checked against its target: 28 pass, 3 fixed by the review, 7 to prove on rev A, 0 fail. The full review is on the board page and in the pack. Rev A must let us measure:

• AI engine time per frame
• Card grade
• Fast lines on a solid ground plane
• Board inside the product CAD, every part checked in 3D
• Tamper switch through the floor
• Flex arms and the bridge
• Call tone out of the cover

8. The design pack

Download the design pack (zip): this request, the KiCad 10 board, a 3D model (STEP), side A and side B drawings (PDF), the parts list, placement, the board outline and drawing layers as Gerbers, and the design review.

Questions: [email protected]