SportsDesign rev O, 28 Oct 2026: smart net posts that make the calls (camera views, ITF Rule 1 and USA Pickleball 2.C checked in the CAD), everything inside the posts; not built

RacketOne

IEMI's one product for tennis and pickleball courts: smart net posts that are their own line and net judge, keep the score, log noise and quiet hours, and report bookings and lights, in one app

A pair of smart net posts, the same Ø76.2 mm posts in the same sleeves, call lets, net touches, sidelines and service lines, pickleball kitchen faults and short serves with no official on court, show each call on the post, keep the score, log noise and paddle pops, check quiet-gear hours, release no-show bookings and send lights-off to the club's own systems, all from inside the posts and in one app.

Who buys it: Tennis and pickleball clubs, parks departments and HOAs with bookable courts near homes, buying per court.
Why it pays: $1,590 + $29/month per court instead of $2,374 + $44/month for ScorePost (with RallyPair, LetTap and 2 BaseClips) and PickleQuiet (with radar and QuietLight) bought separately, before a gate system. Courts rent for $10–20 an hour, so each released no-show hour is worth that again.
Target price: $1,590 per court (pair of smart net posts) + $29/month (target)
First-minute wow: League night with no umpire: a toe on the kitchen line and the south post flashes red with "KITCHEN"; a deep ball near the sideline shows "OUT 14 mm"; a let serve turns both posts amber; at 19:10 court 3 goes back on the booking page.

See the CAD design Concept page

RacketOne concept: the idea and where each part goes — The concept. The CAD design is below, under Printable CAD.

What the research found

And how this design answers it

Rev O (28 Oct 2026): the posts are their own line and net judge. A kitchen camera low in each post, a call light, a tone, a tamper switch and a secure element; the AI camera turned to its half's lines; calls lets, net touches, sideline and service-line in or out, kitchen faults, short serves and post hits alone in club play (far baseline and foot faults assist); every call signed; camera views checked in the CAD
Rev S (27 Oct 2026): the product is now the pair of net posts. Ø76.2 mm round posts, legal for tennis (≤ 15 cm, top ≤ 2.5 cm above the cord) and pickleball (≤ 3 in), with every part inside
The score head above the cord, the solar cap, the base unit, the RallyPads, the fence LineCams, the GateKey and the LightLink relay are gone; their jobs run in the posts or through the club's own booking, gate and lighting systems
Each post: AI camera on its own half, Pi Zero 2 W replay computer, XIAO nRF52840 Sense (mic and motion), LD2450 radar, 2.13 in e-paper score, two team keys and four 18650 cells; the court brain (Walter, ESP32-S3 + LTE-M) in the home post
No detachable part: players score at the post between points
Flagship (27 Oct 2026): one product for tennis and pickleball folds CourtPost, ScorePost and PickleQuiet; the CourtPost court unit is the main unit
ScorePost RallyCall pads become the RallyPad module and talk to the court brain over ESP-NOW, so the score on the screen and the spoken call agree
ScorePost BaseClips become the LineCam module for baseline replays
New GateKey module on the court gate: the QuietLight case, back and halo reused unchanged, with a XIAO ESP32-S3 that opens the existing 12 V lock for a booked phone in its slot (gate access was the one court job with no IEMI answer)
SmartLine AI is not folded: it paints grass fields a few times a season and belongs with grounds products (F6)

Use case

League night at a club with four tennis and pickleball courts, no umpire

PlayersClub or park managerNeighbour

01Trigger: a pickleball league match starts on court 2 at 19:00 in no-official mode; quiet-gear hours start at 19:00
02Detection: the south post's kitchen camera sees a toe on the kitchen line on a volley; the north post's AI camera sees a ball land 14 mm outside the sideline; the cord sensor feels a let serve; court 4 is booked but its radar sees nobody by 19:10
03Alert: the south post flashes red with a tone and shows KITCHEN; the north post shows OUT 14 mm; both posts turn amber for the let; a close ball under the confidence line shows UNSURE in blue and the point is replayed
04Action: every call is signed into the court log with its clip; court 4 goes back on the booking page and lights-off goes to the club's lighting controller at 21:05

Outcome: A league match called fairly with no umpire, a signed record of each call, no wasted court hour and a noise record both sides can read (est.)

How it works

Architecture

01
Sense: in each post an AI camera on its half's lines, a low kitchen camera, the cord and post motion sensor and mic, a radar and two team keys
02
Decide: each post's Pi Zero 2 W and kitchen camera make the line, service and kitchen calls; the XIAO feels lets and net touches; the Walter brain in the home post keeps the score, signs and logs the calls, and runs bookings and quiet hours
03
Send: BLE LE Secure Connections between the posts; the Walter sends MQTT over TLS on LTE-M
04
Tell: each call on the post's light, tone and e-paper; one app for players (score, calls, clips), the club or park (bookings, lights, quiet hours) and neighbours (read-only noise)

Hardware

Real parts, buyable today

Bill of materials: about $664 of parts per court pair at qty 1 (bom.csv), about $1,096 with post fabrication, a net winder, assembly and freight (est.).

Block	Part	Why this part
Brain	DPTechnics Walter (ESP32-S3 + Sequans LTE-M) in the home post	One court brain with its own LTE-M link, so no club Wi-Fi is needed at the court
Line calls	Raspberry Pi AI Camera (IMX500) + Raspberry Pi Zero 2 W in each post	Sidelines, service lines and the T on its own half; on for the whole match
Kitchen calls	Seeed XIAO ESP32-S3 Sense low in each post	Sees the whole 6.1 m kitchen line from 300 mm up for kitchen faults and short serves
Lets and net touches	Seeed XIAO nRF52840 Sense in each post	Its motion sensor feels the cord tied off inside the post; its mic logs noise and pop pitch
Occupancy	Hi-Link HLK-LD2450 radar in each post	No-show release and lights-off without a camera
Score and calls	Waveshare 2.13 in e-paper, two 16 mm keys, NeoPixel Stick 8 and a piezo in each post	Players score and see every call on the post itself
Security	ATECC608 secure element and Omron D2F-01 tamper switch in each post	Signs every call; marks the log if the post is opened
Power	4 x Samsung 35E 18650 + PowerBoost 1000C in each post foot	About 13.8 h of full match play or 10 days of always-on jobs per charge (est.)

Mechanical

Printable CAD

2 parts, generated from code and checked as closed solids. Pick a part to inspect it, or download the STL files to print.

Loading the CAD…

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Open risks we are working on

Baseline calls are seen from the net at a low angle: verdicts there are marked lower confidence until tested on court
The mic sits at the net, not at the neighbour's boundary: levels at homes are estimated from distance until checked against a meter at the property line
Indicative noise monitor only, not a type-approved sound level meter; never a certified compliance result
Players and leagues may not accept electronic line evidence; RacketOne shows evidence, never overrides a call
Cells last about 13.8 h of full match play per charge (est.): busy courts need the lighting-column supply or a pack swap every day or two
Cameras and a mic on public courts need clear signs and a privacy notice
Gate and lights depend on the club's own booking-linked lock and lighting controller; courts without them keep their keys and timers
PlayReplay already sells net-post cameras for pro pickleball and plans to reach clubs: our edge is posts that are the legal equipment themselves, at a one-off price

Design stage only: nothing on this page is for sale. Specifications and prices are targets.