project
12 V to 5 V / 1 A Buck Molecule (TPS54202)
Public Unreviewedby John Lauer
An independently designed 12 V to 5 V, 1 A synchronous buck molecule (TI TPS54202), with calculations, ngspice and PSpice simulation, KiCad 10 schematic and board, and the board laid out and analysed with adom-aiflow.
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Fusion 360 build: every screenshot explained, with links and what Hydrogen adds
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+34−30
fusion-360/README.md+34−30@@ -70,101 +70,105 @@ Every part on this board has its own page on the Adom wiki, with its symbol, foo ### 1. One prompt -+The video opens on the whole job in one sentence, typed into Claude Code inside [Adom Hydrogen](https://wiki.adom.inc/adom/hydrogen). Naming [adom-aiflow](https://wiki.adom.inc/adom/adom-aiflow) is what turns the request into a measured run with a clock, a plan and checks, instead of an open-ended chat. Hydrogen puts VS Code and Claude on the left and live web views on the right, in one window, so everything the run produces shows up beside the conversation that produced it. The AI works in a cloud container, yet it builds the board in Fusion on a real Windows PC through [Adom Bridge](https://wiki.adom.inc/adom/adom-bridge). -The whole request is one sentence typed into Claude Code in Hydrogen. Naming `adom-aiflow` is what turns it into a measured run instead of a chat.+ ### 2. The AI Flow timeline -+AI Flow lays the job out as 21 steps, from intake to the finish line, and shows them as a live timeline in one of Hydrogen's web views. Every step has to pass its own check before the next one starts, and the clock runs from the prompt to the last export. Each arc on the left is a loop-back: a later step found a problem and sent Claude back to an earlier one, and this run had four. Because the timeline is a page in the same window, you watch the plan, the current step and every return as they happen, with no switching between apps. ([AI Flow](https://wiki.adom.inc/adom/adom-aiflow)) -AI Flow lays the job out as 21 steps, from intake to the finish line, and keeps a live clock. Each arc on the left is a loop-back: a later step found a problem and sent Claude back to an earlier one. This run had four.+ ### 3. Parts from the Adom wiki +Every part on the board comes from its own component page on the Adom wiki, like the [TPS54202DDCR](https://wiki.adom.inc/adom/tps54202ddcr) here. Each page carries a symbol, a footprint, a 3D model checked Z-up, and Mouser, DigiKey and LCSC numbers, so the AI starts from parts that were already verified instead of guessing at CAD. Hydrogen opens these pages in a web view next to the chat, so the part Claude is reasoning about is on screen while it does. Parts that are not on the wiki yet are fetched and built by [Chip Fetcher](https://wiki.adom.inc/adom/adom-chip-fetcher).+  -Every part comes from its Adom wiki component page: a 3D model checked Z-up, the symbol and footprint, and Mouser, DigiKey and LCSC numbers.+The green power LED, [IN-S63BTG](https://wiki.adom.inc/adom/in-s63btg), shows a wiki feature you won't find on other part sites: a states widget, with one 3D model per state, off and lit. A viewer can show the board with the LED on, and a probing simulation can check that the LED should be lit at that test step. The widget is one of the reusable [component widgets](https://wiki.adom.inc/adom/component-widgets) any part page can carry. Flipping it from Off to On in the video is a live view of the model, not a picture.  -The LED's page carries one 3D model per state, off and lit, so a viewer or a probing simulation shows the part as it should look.- ### 4. The bridge signs in to Fusion +The PC for this step was not signed in to Fusion yet, so the [Fusion Bridge](https://wiki.adom.inc/adom/fusion-bridge) handled the sign-in itself: it pressed Fusion's Sign in button and drove the Autodesk page in the browser. It never types a password or a 2FA code; those stay with the person. This is the part most automation stops at, because a signed-out app is a dead end for an AI. Hydrogen and Adom Bridge reach a whole desktop, not just one program, so the AI can get past the sign-in and keep going.+  -The PC used for this step wasn't signed in to Fusion yet, so the Fusion Bridge drove the sign-in itself: Fusion's Sign in button, then the Autodesk page in the browser. It never types a password or a 2FA code; those stay with the person.+Fusion then said the license seat was still in use on another PC. The bridge chose to suspend Fusion there and continue here, the decision a person would make, and carried on. Hydrogen drives several Windows PCs as one mesh through [Adom Bridge](https://wiki.adom.inc/adom/adom-bridge), so moving the seat between machines is a normal part of a run, not an interruption.  -The license seat was still on another PC, so the bridge moved it: suspend Fusion there, continue here.- ### 5. One project library +AI Flow builds one Fusion library for the project, with a symbol, a footprint and a bound 3D model for every part. Here is the TPS54202 symbol, drawn with its chip outline so the schematic reads like the real package. The Fusion Bridge creates the library through Fusion's own API and commands, with no library dialogs to click through. A Fusion parts library is normally hours of careful hand work; here it is one step of the run. ([Fusion Bridge](https://wiki.adom.inc/adom/fusion-bridge))+  -+The footprint comes from the same wiki page as the symbol, so pads, pin numbers and the 3D model agree by construction. Every part gets the same treatment, down to the 0.5 mm [probe test pad](https://wiki.adom.inc/adom/testpoint-pad-0-5mm) that the probing workcell lands on. Because the library is built from verified wiki data, the board that comes out of Fusion matches the parts you would order. -AI Flow builds one Fusion library for the project: a symbol, a footprint and a bound 3D model for every part, the TPS54202 symbol drawn with its chip outline.+ ### 6. The schematic -+Claude draws the schematic live in Fusion, in labelled groups. Every pin is checked against the netlist the circuit step produced, so a wrong connection fails the step instead of reaching the board. The Fusion Bridge places and wires parts through Fusion's own electronics commands, so the drawing is real Fusion data you can open and edit, not an imported picture. Hydrogen and the bridge let the AI work Fusion's electronics editor the way a person would, but by command, a whole schematic in minutes. -Claude draws the schematic live in Fusion in labelled groups, and every pin is checked against the netlist.+ ### 7. SPICE -+Before any copper, the circuit is simulated in ngspice, running right in the container: the soft start from 12 V, a load step from 0.5 A to 1 A, and the inductor current through both. The dashboard can also run the same circuit in LTspice or in PSpice for TI on a Windows PC, one click each, to cross-check the result. Hydrogen keeps the plots in a web view next to the design, so the numbers that justify each part value sit on the same screen as the circuit. ([SPICE skills](https://wiki.adom.inc/adom/adom-spice-skillpack)) -ngspice runs in the container: the soft start from 12 V, a step from 0.5 A to 1 A, and the inductor current through both.+ ### 8. Placement, and the first loop-back +Claude places the parts, then AI Flow checks the result against the layout rules before routing starts. Here the check found the switch-node trace detouring 18.9 mm because of where C5 sat, so the timeline drew an arc and sent Claude back to placement. The glowing ring marks C5 in its first spot. This is the core of AI Flow: the AI is graded step by step, and a failed check sends it back instead of letting a bad board through.+  -The router's check found the switch-node trace detouring 18.9 mm because of where C5 sat, so AI Flow sent Claude back to placement.+C5 moved next to the pins it serves, and the switch-node loop got short. A second loop-back came from routing: the VOUT feed passed 0.15 mm from R6's LED pad, so Claude turned R6 to face the feed. Each return is recorded on the timeline with its reason, so you can audit every decision the AI made, not just the final board.  -C5 moved next to the pins it serves. A second loop-back turned R6 so its pad faces the output feed.- ### 9. Routing, heatsink vias and pours +The board is routed to 100 percent, then the heatsink vias, the copper pours and the rounded corners each land as their own checked pass. A review of the vias found U1 had only 1 of its 6 planned heatsink vias, and AI Flow sent Claude back to routing: clear the copper, re-route around U1, place the full array and pour again. The six vias now tie U1's ground pin to the bottom ground plane, all within 2.75 mm. Every copper change happens in Fusion through the bridge's commands, so the result is a normal Fusion board design. ([AI Flow](https://wiki.adom.inc/adom/adom-aiflow))+  -The board is routed to 100 percent, then the heatsink vias, the pours and the rounded corners each land as their own checked pass. A review of the vias then found U1 had only 1 of its 6 planned heatsink vias, and AI Flow sent Claude back to routing: clear the copper, re-route around U1, place the full array, pour again. The six vias now tie U1's ground pin to the bottom ground plane, all within 2.75 mm.+The video then shows each pour net in turn, highlighted on its own. GND fills most of the board and gives the regulator's heat somewhere to go. Walking the nets one at a time is how an engineer checks a pour, and here the AI does it as a step of the run.  -+The switch node gets a small, solid SW patch, kept short on purpose because it is the noisiest net on a buck. A large SW pour would radiate; a tight one keeps the hot loop small. That judgement comes from AI Flow's power-layout rules, which the run follows and checks. -Each pour net in turn: GND, then the small solid SW patch.+ ### 10. Current and heat -+[Adom Fields](https://wiki.adom.inc/adom/adom-fields) solves the real copper of the finished board for current density and temperature, and shows it in 3D in a Hydrogen web view. The peak current density is 53 A/mm², and the heatsink vias carry about a third of U1's 0.25 W into the ground plane. This is a field solve on the real layout, not a rule of thumb. The analysis is a step of the run, so a result over budget sends Claude back to fix the copper instead of just being reported. -Adom Fields solves the real copper for current density and temperature. Peak current density is 53 A/mm², and the vias carry about a third of U1's 0.25 W into the plane.+ ### 11. Silkscreen -+The silkscreen is laid down one item at a time: framed tags on every edge contact, matched frames on the corner pins, and each value in small text beside its reference. Text heights follow the fab's minimums, so every label prints. The rules that came out of this run, such as frame sizes, equal widths and minimum text heights per fab, are now part of [AI Flow](https://wiki.adom.inc/adom/adom-aiflow)'s silkscreen skill for every future board. Good silkscreen is what makes a board easy to assemble, probe and debug. -Framed tags on every edge contact, matched frames on the corner pins, and each value in small text beside its reference. The silkscreen rules that came out of this run (frame sizes, equal widths, minimum text heights per fab) are now part of AI Flow's silkscreen skill.+ ### 12. The board in 3D -+Fusion's 3D view shows every part sitting flat on its pads, which is the check that the library's 3D models were bound correctly. Each model came from its wiki page, already checked for orientation. The same board is in the 3D viewer at the top of this page, exported from Fusion and running in the wiki's own viewer. -Every part sits flat on its pads in Fusion's 3D view.+ ### 13. The finish line -+The timeline reaches 21 of 21 steps: the finish line is Gerbers, a BOM and a pick-and-place file exported from Fusion. AI Flow only calls the run finished when every step has passed its check, so the board is routed, design-rule clean, poured, analysed and exported. The clock stops at 2 h 42 min from the prompt. What you get is a real Fusion project plus the files a fab needs. -21 of 21 steps, the finish line reached: Gerbers, BOM and pick-and-place exported.+ ## What it cost