An excellent hardware engineer with RF design experience

CMT is seeking bids for time and cost to create a hardware design and layout for a small circuit board

based on the TI CC2652 microcontroller, plus supporting circuitry (e.g. power, clocks, integrated BLE

antenna, sensor connections, etc)This board will be worn at the nape of the neck, integrated into a sof

skull cap for sports and other highly physical activities. As such, it cannot have any sharp corners or

significant protrusions that may cause injury to the wearer. It will require a sof slimline case or

conformal coating to protect it from sweat and rain, and ideally use water resistant connectors for the

external sensors. External sensors will consist of eight (8) fabric-based sensors integrated into the cap.

Nominally each sensor is connected via a mico-coax cable, for 16 total conductors.

Ideally this board will be as tightly packed and physically small as possible. In many ways, this board will

be quite similar to the TI “SensorTag” reference design (attached). Note especially RF design guidelines

and section 7.3, Layout recommendations. High level requirements follow:

I. Physical

a. Total board size should not exceed 30 x 40mm and be as thin and light as possible.

b. Board is expected to be 4 layer unless significant advantages can be gained otherwise.

c. All corners should be rounded w/ min 4-5mm radius, larger radii preferred if space.

d. SMD Carrier for CR-2032 battery.

e. Ideally, all components (pehaps excluding the battery if necessary) should be on a single

side, with no sharp through-hole protrusions. Some variation allowed where necessary.

II. External Connections

a. Battery (SMD carrier for CR-2032)

b. External Sensors (for 8 fabric sensors)

i. 16 conductor connector – perhaps FPC pr FFC, even direct solder is a

consideration (especially with conformal coat). Other suggestions welcome.

ii. Note that sensors are capacitive, design must respect this appropriately.

c. RF Antenna

i. Should have an integrated BLE antenna on the board...

ii. But an external antenna design could be possible – make recommendations

iii. Design for BLE 5 long-range (Need >100m realistic usable range. General use

case: flat outdoor field with few obstructions, but likely other BLE interference.)

III. On board sensors

a. On-board sensors shall be similar to a subset of the TI dev board, but alternative sensors

selections may be made as long as basic functionality remains. Alternative selections to

reduce power, cost, and/or physical board size are encouraged.

b. Ambient Light (OPT3001 or similar)

c. Infrared Temperature (TMP007 or similar)

d. Ambient Temperature (HDC1000 or similar)

e. Humidity (HDC1000 or similar)

f. Accelerometer (MCU-9250 or similar)

i. In particular, this and the Gyro seem to be most likely to be damaged. High “G”

force models are preferred. Ideally should handle impacets in the 300 – 500 G

range without damage, even if beyond the usable range of the sensor.

g. Gyroscope (MCU-9250 or similar)

h. Pressure (Altimiter) (BMP280 or similar)

IV. Future considerations

a. To the extent allowable, future-proof the design by considering the following variants,

and making alllowances and accomodations, or help make them easy to add later.

i. TI CC 1352 Sub-GHz variant for extrememly long rang (> 1km)

ii. External antenna variant – using a flexible wire antenna around the hat band

iii. Variant/Option to include a TI CC2590 or CC2592 LNA/Power Amplifier for

additional range (BLE/CC2652 2.4 GHz version only)

iv. A microswitch push button or two for debug and test (optionally populated for

production too)

v. Additional Flash memory for keeping a complete lifecycle data history. (2-4M)

vi. Possible micro-USB Debug/Programming port (though most programming

should be OTA)

Elektrisk ingeniørvitenskap Microcontroller PCB Layout

Prosjekt-ID: #17274912

Om prosjektet